Diversity of staphylococcal cassette chromosome mec structures in methicillin-resistant Staphylococcus epidermidis and Staphylococcus haemolyticus strains among outpatients from four countries.

PubMed

Ruppé, Etienne; Barbier, François; Mesli, Yasmine; Maiga, Aminata; Cojocaru, Radu; Benkhalfat, Mokhtar; Benchouk, Samia; Hassaine, Hafida; Maiga, Ibrahim; Diallo, Amadou; Koumaré, Abdel Karim; Ouattara, Kalilou; Soumaré, Sambou; Dufourcq, Jean-Baptiste; Nareth, Chhor; Sarthou, Jean-Louis; Andremont, Antoine; Ruimy, Raymond

2009-02-01

In staphylococci, methicillin (meticillin) resistance (MR) is mediated by the acquisition of the mecA gene, which is carried on the size and composition variable staphylococcal cassette chromosome mec (SCCmec). MR has been extensively studied in Staphylococcus aureus, but little is known about MR coagulase-negative staphylococci (MR-CoNS). Here, we describe the diversity of SCCmec structures in MR-CoNS from outpatients living in countries with contrasting environments: Algeria, Mali, Moldova, and Cambodia. Their MR-CoNS nasal carriage rates were 29, 17, 11, and 31%, respectively. Ninety-six MR-CoNS strains, comprising 75 (78%) Staphylococcus epidermidis strains, 19 (20%) Staphylococcus haemolyticus strains, 1 (1%) Staphylococcus hominis strain, and 1 (1%) Staphylococcus cohnii strain, were analyzed. Eighteen different SCCmec types were observed, with 28 identified as type IV (29%), 25 as type V (26%), and 1 as type III (1%). Fifteen strains (44%) were untypeable for their SCCmec. Thirty-four percent of MR-CoNS strains contained multiple ccr copies. Type IV and V SCCmec were preferentially associated with S. epidermidis and S. haemolyticus, respectively. MR-CoNS constitute a widespread and highly diversified MR reservoir in the community.

First detection of livestock-associated meticillin-resistant Staphylococcus aureus CC398 in bulk tank milk in the United Kingdom, January to July 2012

PubMed Central

Paterson, G K; Larsen, J; Harrison, E M; Larsen, A R; Morgan, F J; Peacock, S J; Parkhill, J; Zadoks, R N; Holmes, M A

2013-01-01

Livestock-associated meticillin-resistant Staphylococcus aureus belonging to clonal complex 398 (LA-MRSA CC398) is an important cause of zoonotic infections in several countries, but there is only a single published report of this lineage from the United Kingdom (UK). Here, we describe the isolation of LA-MRSA CC398 from bulk tank milk from five geographically dispersed farms in the UK. Our findings suggest that LA-MRSA CC398 is established in livestock in the UK. Awareness of the potential occupational risks and surveillance in other food-producing animal species should be promoted. PMID:23241232

Changing molecular epidemiology and high rates of mupirocin resistance among meticillin-resistant Staphylococcus aureus in Singaporean hospitals.

PubMed

Hon, Pei Yun; Koh, Tse Hsien; Tan, Thean Yen; Krishnan, Prabha; Leong, Janice Wai-Yeng; Jureen, Roland; Chan, Joey; Tee, Nancy Wen-Sim; Murugesh, Jagadeesan; Chan, Kian Sing; Hsu, Li Yang

2014-03-01

A prospective cross-sectional study was performed to determine the continuing shift in the molecular epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) in Singapore. In total, 666 MRSA isolates from screening cultures performed between 7 and 20 January 2013 were obtained from all seven public sector hospitals in Singapore and were subjected to molecular typing using multilocus variable-number tandem-repeat fingerprinting with confirmatory multilocus sequencing typing for clustered isolates. Isolates were also tested for the presence of the orfX-ACME insert and the high-level mupirocin resistance gene ileS-2. The major circulating clones in Singaporean hospitals were ST22 (63.2%), ST45 (18.9%) and ST239 (10.7%). The orfX-ACME insert was only found in ST239 isolates (31/71, 43.7%), but ileS-2 was found in 207 (31.1%) of the MRSA isolates, varying between 10.0% and 47.8% among the hospitals. In conclusion, the molecular epidemiology of MRSA in Singaporean hospitals has continued to change, with ST45 now replacing ST239 in addition to the ongoing replacement of the latter by ST22. Although a greater proportion of ST239 isolates carry the orfX-ACME insert, the actual clinical impact may be marginal as ST239 MRSA continues to decline. Finally, high-level mupirocin resistance rates are remarkably high in local healthcare-associated MRSA, with implications for MRSA decolonisation and infection prevention. Further surveillance is required to monitor the changing epidemiological trends. Copyright © 2013 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Prevalence of genes encoding extracellular virulence factors among meticillin-resistant Staphylococcus aureus isolates from the University Hospital, Olomouc, Czech Republic.

PubMed

Sauer, P; Síla, J; Stosová, T; Vecerová, R; Hejnar, P; Vágnerová, I; Kolár, M; Raclavsky, V; Petrzelová, J; Lovecková, Y; Koukalová, D

2008-04-01

A rather fast and complicated progression of an infection caused by some strains of Staphylococcus aureus could be associated with the expression and co-action of virulence factor complexes in these strains. This study screened the antibiotic susceptibility and prevalence of virulence markers in isolates of meticillin-resistant S. aureus (MRSA) obtained from patients hospitalized at the University Hospital in Olomouc, Czech Republic. A total of 100 isolates was screened for 13 genes encoding extracellular virulence determinants (tst, pvl, eta, etb, sea, seb, sec, sed, see, seg, seh, sei and sej) and for their distribution in sample types. Eighty-nine isolates were positive for at least one of the genes. Genes for etb, pvl, see and seh were not detected in any of the MRSA isolates. No statistically significant differences in the occurrence of the determinants studied among sample types were found.

Spa typing and identification of pvl genes of meticillin-resistant Staphylococcus aureus isolated from a Libyan hospital in Tripoli.

PubMed

Ahmed, Mohamed O; Baptiste, Keith E; Daw, Mohamed A; Elramalli, Asma K; Abouzeed, Yousef M; Petersen, Andreas

2017-09-01

The purpose of the study was to investigate the molecular characteristics of meticillin-resistant Staphylococcus aureus (MRSA) isolated from clinical sources in Tripoli, Libya. A total of 95 MRSA strains collected at the Tripoli medical Centre were investigated by spa typing and identification of the Panton-Valentine Leukocidin (pvl) genes. A total of 26 spa types were characterized and distributed among nine clonal complexes; CC5 (n=32), CC80 (n=18), CC8 (n=17) and CC22 (n=12) were the most prevalent clonal complexes. In total, 34% of the isolates were positive for PVL. This study demonstrated the presence of CA-MRSA and pvl positive strains in hospital settings and underlines the importance of using molecular typing to investigate the epidemiology of MRSA. Preventative measures and surveillance systems are needed to control and minimize the spread of MRSA in the Libyan health care system. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) among human MRSA isolates, European Union/European Economic Area countries, 2013

PubMed Central

Kinross, Pete; Petersen, Andreas; Skov, Robert; Van Hauwermeiren, Evelyn; Pantosti, Annalisa; Laurent, Frédéric; Voss, Andreas; Kluytmans, Jan; Struelens, Marc J; Heuer, Ole; Monnet, Dominique L

2017-01-01

Currently, surveillance of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) in humans in Europe is not systematic but mainly event-based. In September 2014, the European Centre for Disease Prevention and Control (ECDC) initiated a questionnaire to collect data on the number of LA-MRSA from human samples (one isolate per patient) from national/regional reference laboratories in European Union/European Economic Area (EU/EEA) countries in 2013. Identification of LA-MRSA as clonal complex (CC) 398 by multilocus sequence typing (MLST) was preferred, although surrogate methods such as spa-typing were also accepted. The questionnaire was returned by 28 laboratories in 27 EU/EEA countries. Overall, LA-MRSA represented 3.9% of 13,756 typed MRSA human isolates, but it represented ≥ 10% in five countries (Belgium, Denmark, Spain, the Netherlands and Slovenia). Seven of the reference laboratories did not type MRSA isolates in 2013. To monitor the dispersion of LA-MRSA and facilitate targeted control measures, we advocate periodic systematic surveys or integrated multi-sectorial surveillance. PMID:29113628

Livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) among human MRSA isolates, European Union/European Economic Area countries, 2013.

PubMed

Kinross, Pete; Petersen, Andreas; Skov, Robert; Van Hauwermeiren, Evelyn; Pantosti, Annalisa; Laurent, Frédéric; Voss, Andreas; Kluytmans, Jan; Struelens, Marc J; Heuer, Ole; Monnet, Dominique L

2017-11-01

Currently, surveillance of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) in humans in Europe is not systematic but mainly event-based. In September 2014, the European Centre for Disease Prevention and Control (ECDC) initiated a questionnaire to collect data on the number of LA-MRSA from human samples (one isolate per patient) from national/regional reference laboratories in European Union/European Economic Area (EU/EEA) countries in 2013. Identification of LA-MRSA as clonal complex (CC) 398 by multilocus sequence typing (MLST) was preferred, although surrogate methods such as spa -typing were also accepted. The questionnaire was returned by 28 laboratories in 27 EU/EEA countries. Overall, LA-MRSA represented 3.9% of 13,756 typed MRSA human isolates, but it represented ≥ 10% in five countries (Belgium, Denmark, Spain, the Netherlands and Slovenia). Seven of the reference laboratories did not type MRSA isolates in 2013. To monitor the dispersion of LA-MRSA and facilitate targeted control measures, we advocate periodic systematic surveys or integrated multi-sectorial surveillance.

[Impact of nasal colonization by methicillin-resistant Staphylococcus aureus among geriatric intermediate care facility patients].

PubMed

Giraud, Karine; Chatap, Guy; Bastuji-Garin, Sylvie; Vincent, Jean-Pierre

2004-12-04

To evaluate the impact of nasal carriage of Methicillin Resistant Staphylococcus aureus (MRSA) on antibiotic cost, infection morbidity, mortality and length of stay in a geriatric population. 341 consecutive elderly patients (mean age 83.4 +/- 8.7 years) admitted to an intermediate care facility were prospectively include between November 1998 and October 1999. Nasal swab cultures were taken on admission. In sixty patients (17.6%) no nasal swab was taken. Among the 281 patients screened, 52 were identified as MRSA carriers. The principle predictive factors were: diabetes (p=0,046), sores (p=0,03), malnutrition (p=0,02), polypathology (p=0,02) and prolongation of previous hospitalisation (p=0,09). Nasal carriage of MRSA on admission to the facility was not a deleterious prognostic factor regarding duration of stay, infectious morbidity and antibiotic cost, but was associated with higher mortality risk.

Successful control of nosocomial transmission of the USA300 clone of community-acquired meticillin-resistant Staphylococcus aureus in a UK paediatric burns centre.

PubMed

Patel, M; Thomas, H C; Room, J; Wilson, Y; Kearns, A; Gray, J

2013-08-01

An outbreak of the PVL-positive USA300 clone of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) occurred in a UK paediatric burns centre from January to February 2010. Four patients, two staff members and one family member of a patient were affected. The outbreak strain had similar antibiotic susceptibilities to other MRSA seen in the hospital, and was only identified when a patient and a staff member presented simultaneously with skin infections. Infection control measures included screening and decolonization of staff and patients, environmental sampling and enhanced cleaning. Isolation of the outbreak strain from an asymptomatic staff member and the environment demonstrates the potential for CA-MRSA to survive and become endemic in UK hospitals. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Nasal carriage of multi-drug resistant Panton-Valentine leucocidin-positive methicillin-resistant Staphylococcus aureus in children in Tripoli-Libya.

PubMed

Al-haddad, Omaima H; Zorgani, Abdulaziz; Ghenghesh, Khalifa Sifaw

2014-04-01

Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.

Prevention of meticillin-resistant Staphylococcus aureus bloodstream infections in European hospitals: moving beyond policies.

PubMed

Borg, M A; Hulscher, M; Scicluna, E A; Richards, J; Azanowsky, J-M; Xuereb, D; Huis, A; Moro, M L; Maltezou, H C; Frank, U

2014-08-01

There is evidence that meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia can be reduced with improved infection control and antibiotic stewardship. To survey infection control and antibiotic stewardship practices within European hospitals and to identify initiatives that correlate with reduced MRSA prevalence. Online questionnaires were sent to European hospitals about their surveillance, hand hygiene, intravenous device management, admission screening, isolation, antibiotic prescribing, hospital demographics and MRSA blood culture isolates during 2010. In all, 269 replies were received from hospitals in 29 European countries. Lower MRSA prevalence showed significant association with presence of incidence surveillance, performance of root cause analysis, mandatory training requirements for hand hygiene, accountability measures for persistent non-compliance, and multi-stakeholder teamwork in antibiotic prescribing. Presence of policies on intravenous catheter insertion and management showed no variation between different MRSA prevalence groups. However, low-prevalence hospitals reported more competency assessment programmes in insertion and maintenance of peripheral and central venous catheters. Hospitals from the UK and Ireland reported the highest uptake of infection control and antibiotic stewardship practices that were significantly associated with low MRSA prevalence, whereas Southern European hospitals exhibited the lowest. In multiple regression analysis, isolation of high-risk patients, performance of root cause analysis, obligatory training for nurses in hand hygiene, and undertaking joint ward rounds including microbiologists and infectious disease physicians remained significantly associated with lower MRSA prevalence. Proactive infection control and antibiotic stewardship initiatives that instilled accountability, ownership, teamwork, and validated competence among healthcare workers were associated with improved MRSA outcomes. Copyright �

Effect of manuka honey on the expression of universal stress protein A in meticillin-resistant Staphylococcus aureus.

PubMed

Jenkins, Rowena; Burton, Neil; Cooper, Rose

2011-04-01

Staphylococcus aureus is an important pathogen that can cause many problems, from impetigo to endocarditis. With its continued resistance to multiple antibiotics, S. aureus remains a serious health threat. Honey has been used to eradicate meticillin-resistant S. aureus (MRSA) strains from wounds, but its mode of action is not yet understood. Proteomics provides a potent group of techniques that can be used to analyse differences in protein expression between untreated bacterial cells and those treated with inhibitory concentrations of manuka honey. In this study, two-dimensional (2D) electrophoresis was combined with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) to determine the identities of proteins whose levels of expression were changed at least two-fold following treatment with manuka honey. Protein extracts were obtained from cells grown in tryptone soy broth (with or without manuka honey) by mechanical disruption and were separated on 2D polyacrylamide gels. A protein was isolated in gels prepared from untreated cell extract that was absent from gels made using honey-treated cell extract. Using MALDI-TOF MS, the protein was identified as universal stress protein A (UspA). Downregulation of this protein was confirmed by real-time polymerase chain reaction (PCR), which showed a 16-fold downregulation in honey-treated cells compared with untreated samples. This protein is involved in the stress stamina response and its downregulation could help to explain the inhibition of MRSA by manuka honey. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Staphylococcus aureus nasal carriage in Ukraine: antibacterial resistance and virulence factor encoding genes.

PubMed

Netsvyetayeva, Irina; Fraczek, Mariusz; Piskorska, Katarzyna; Golas, Marlena; Sikora, Magdalena; Mlynarczyk, Andrzej; Swoboda-Kopec, Ewa; Marusza, Wojciech; Palmieri, Beniamino; Iannitti, Tommaso

2014-03-05

The number of studies regarding the incidence of multidrug resistant strains and distribution of genes encoding virulence factors, which have colonized the post-Soviet states, is considerably limited. The aim of the study was (1) to assess the Staphylococcus (S.) aureus nasal carriage rate, including Methicillin Resistant S. aureus (MRSA) strains in adult Ukrainian population, (2) to determine antibiotic resistant pattern and (3) the occurrence of Panton Valentine Leukocidine (PVL)-, Fibronectin-Binding Protein A (FnBPA)- and Exfoliative Toxin (ET)-encoding genes. Nasal samples for S. aureus culture were obtained from 245 adults. The susceptibility pattern for several classes of antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The virulence factor encoding genes, mecA, lukS-lukF, eta, etb, etd, fnbA, were detected by Polymerase Chain Reaction (PCR). The S. aureus nasal carriage rate was 40%. The prevalence of nasal MRSA carriage in adults was 3.7%. LukS-lukF genes were detected in over 58% of the strains. ET-encoding genes were detected in over 39% of the strains and the most prevalent was etd. The fnbA gene was detected in over 59% of the strains. All MRSA isolates tested were positive for the mecA gene. LukS-lukF genes and the etd gene were commonly co-present in MRSA, while lukS-lukF genes and the fnbA gene were commonly co-present in Methicillin Sensitive S. aureus (MSSA) isolates. No significant difference was detected between the occurrence of lukS-lukF genes (P > 0.05) and the etd gene (P > 0.05) when comparing MRSA and MSSA. The occurrence of the fnbA gene was significantly more frequent in MSSA strains (P < 0.05). In Ukraine, S. aureus is a common cause of infection. The prevalence of S. aureus nasal carriage in our cohort of patients from Ukraine was 40.4%. We found that 9.1% of the strains were classified as MRSA and all MRSA isolates tested

Air and surface contamination patterns of meticillin-resistant Staphylococcus aureus on eight acute hospital wards.

PubMed

Creamer, E; Shore, A C; Deasy, E C; Galvin, S; Dolan, A; Walley, N; McHugh, S; Fitzgerald-Hughes, D; Sullivan, D J; Cunney, R; Coleman, D C; Humphreys, H

2014-03-01

Meticillin-resistant Staphylococcus aureus (MRSA) can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients. To investigate associations between MRSA isolates recovered from air and environmental surfaces with those from patients when undertaking extensive patient and environmental sampling. This was a prospective observational study of patients and their environment in eight wards of a 700-bed tertiary care hospital during 2010 and 2011. Sampling of patients, air and surfaces was carried out on all ward bays, with more extended environmental sampling in ward high-dependency bays and at particular times of the day. The genetic relatedness of isolates was determined by DNA microarray profiling and spa typing. MRSA was recovered from 30/706 (4.3%) patients and from 19/132 (14.4%) air samples. On 9/132 (6.8%) occasions both patient and air samples yielded MRSA. In 32 high-dependency bays, MRSA was recovered from 12/161 (7.4%) patients, 8/32 (25%) air samples, and 21/644 (3.3%) environmental surface samples. On 10/132 (7.6%) occasions, MRSA was isolated from air in the absence of MRSA-positive patients. Patient demographic data combined with spa typing and DNA microarray profiling revealed four likely transmission clusters, where patient and environmental isolates were deemed to be very closely related. Air sampling yielded MRSA on frequent occasions, especially in high-dependency bays. Environmental and air sampling combined with patient demographic data, spa typing and DNA microarray profiling indicated the presence of clusters that were not otherwise apparent. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Staphylococcus aureus nasal carriage and its antibiotic resistance profiles in children in high altitude areas of Southwestern China.

PubMed

Gong, Zongrong; Shu, Min; Xia, Qing; Tan, Shan; Zhou, Wei; Zhu, Yu; Wan, Chaomin

2017-06-01

To describe the epidemiological profile of nasal carriage of Staphylococcus aureus (S. aureus) strains, its antibiotic resistance and mecA and Panton Valentine leukocidin (PVL) genes presence, in school children residing in high altitude areas of Southwestern China. The cross sectional study screened nasal swabs taken from students for S.aureus. PCR was performed to identify mecA and PVL genes. Of the total 314 children 5.10% (16/314) was detected S.aureus. The resistance of isolated strains to penicillin, erythromycin, clindamycin, rifampicin and cefoxitin was 100%, 81.3%, 81.3%, 0.0%, and 6.3% respectively. No strains demonstrated resistance to vancomycin; expression of mecA gene was detected in 3 isolates and 10 isolates were PVL-positive. S. aureus was detected in 5.10% (16/314) of the study population; 0.96% (3/314) had methicillin resistant S.aureus (MRSA); expression of the mecA and PVL genes were detected in 3 and 10 isolates respectively.

Methicillin-resistant Staphylococcus aureus nasal carriage and infection among patients with diabetic foot ulcer.

PubMed

Lin, Shin-Yi; Lin, Nai-Yu; Huang, Yu-Yao; Hsieh, Chi-Chun; Huang, Yhu-Chering

2018-06-04

To evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in patients with diabetic foot ulcer (DFU) in Taiwan, and to assess the concordance between colonizing and clinical MRSA isolates from the patients. A total of 354 nasal specimens were collected from 112 to 242 diabetic patients with and without foot ulcer, respectively. MRSA clinical isolates from DFU wound cultures were collected for comparison. Nasal carriage rate of S. aureus and MRSA was similar between diabetic patients with and without foot ulcer (15.2% vs. 16.9% for S. aureus and 5.4% vs. 1.7% for MRSA). Nasal S. aureus colonization was an independent predictor for wound S. aureus infection (Odds ratio [OR]: 5.33, 95% confidence interval [CI]: 1.61-17.59), so did nasal MRSA colonization (OR: 19.09, 95% CI: 2.12-171.91). The levels of glycated hemoglobin, and the usage with immunosuppressant agent were associated with S. aureus nasal colonization while oral hypoglycemic agent usage a protective factor. Sequence type 59/staphylococcal chromosome cassette mec IV or V, the local endemic community-associated clone, accounted for 42% and 70% of the clinical and colonizing isolates, respectively. Six of 10 patients with paired colonizing and clinical isolates, either MRSA or methicillin-sensitive S. aureus, had a genetically identical strain from a single patient. Less than one-fifth of patients with DFU have nasal S. aureus, including MRSA, colonization; however, the colonization is significantly associated with S. aureus diabetic foot infection. Screening for S. aureus colonizing status in DFU patients might have a potential clinical implication. Copyright © 2018. Published by Elsevier B.V.

Whole-genome comparison of meticillin-resistant Staphylococcus aureus CC22 SCCmecIV from people and their in-contact pets.

PubMed

Loeffler, Anette; McCarthy, Alex; Lloyd, David H; Musilová, Eva; Pfeiffer, Dirk U; Lindsay, Jodi A

2013-10-01

Meticillin-resistant Staphylococcus aureus (MRSA) infections remain important medical and veterinary challenges. The MRSA isolated from dogs and cats typically belong to dominant hospital-associated clones, in the UK mostly EMRSA-15 (CC22 SCCmecIV), suggesting original human-to-animal transmission. Nevertheless, little is known about host-specific genetic variation within the same S. aureus lineage. To identify host-specific variation amongst MRSA CC22 SCCmecIV by comparing isolates from pets with those from in-contact humans using whole-genome microarray. Six pairs of MRSA CC22 SCCmecIV from human carriers (owners and veterinary staff) and their respective infected in-contact pets were compared using a 62-strain whole-genome S. aureus microarray (SAM-62). The presence of putative host-specific genes was subsequently determined in a larger number of human (n = 47) and pet isolates (n = 93) by PCR screening. Variation in mobile genetic elements (MGEs) occurred frequently and appeared largely independent of host and in-contact pair. A plasmid (SAP078A) encoding heavy-metal resistance genes (arsR, arsA, cadA, cadC, mco and copB) was found in three of six human and none of six animal isolates. However, only two of four resistance genes were associated with human hosts (P = 0.015 for arsA and cadA). The variation found amongst MGEs highlights that genetic adaptation in MRSA continues. However, host-specific MGEs were not detected, which supports the hypothesis that pets may not be natural hosts of MRSA CC22 and emphasizes that rigorous hygiene measures are critical to prevent contamination and infection of dogs and cats. The host specificity of individual heavy-metal resistance genes warrants further investigation into different selection pressures in humans and animals. © 2013 ESVD and ACVD.

[Study of methicillin-resistant Staphylococcus aureus colonization among intermediate-care facility patients].

PubMed

Giret, P; Roblot, F; Poupet, J Y; Thomas, P; Lussier-Bonneau, M D; Pradère, C; Becq-Giraudon, B; Fauchère, J L; Castel, O

2001-08-01

Prevalence of methicillin-resistant Staphylococcus aureus is high in the Poitiers teaching hospital, particularly in the intermediate care facilities. We performed a survey of methicillin-resistant Staphylococcus aureus colonization in the intermediate care facilities and 265 patients were included. Nasal, cutaneous and wound swab cultures were done at the time of admission and at the time of the patients' departure. A decolonization procedure of methicillin-resistant Staphylococcus aureus carriers was performed using nasal application of fusidic acid and different soaps for the skin. At entry, 17.7% of patients were methicillin-resistant Staphylococcus aureus carriers (of at least one location). At departure, 30.4% were methicillin-resistant Staphylococcus aureus carriers. Among methicillin-resistant Staphylococcus aureus non-carriers at entry, 24.3% became methicillin-resistant Staphylococcus aureus carriers. The principal risk factor of carriage was the initial presence of a wound (RR = 3.6). The incidence rate of methicillin-resistant Staphylococcus aureus infection among the 265 patients included was 3%. The systematic screening of patients at the time of admission is expensive and isolation technically hard to manage in the intermediate care facilities. The risk factor we found in this study allow us to propose a 'light' screening limited to patients with wounds.

Methicillin-resistant Staphylococcus aureus nasal carriage between healthy students of medical and nonmedical universities.

PubMed

Abroo, Soleiman; Hosseini Jazani, Nima; Sharifi, Yaeghob

2017-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a challenge for public health, and community-acquired (CA) infections seem to be increasing among people in different areas. A total of 700 healthy student volunteers residing in dormitories of universities in Urmia, Iran, were enrolled in this study. After identification of the isolates, antibiotic susceptibility, presence of mecA and pvl genes, and staphylococcal cassette chromosome mec (SCCmec) typing were evaluated. Nasal screening identified 137 (19.6%) carriers of S aureus, and 18 (13.14%) were MRSA isolates. The antimicrobial susceptibility patterns of isolates revealed high resistance to penicillin (93.4%). All isolates were sensitive to vancomycin. The SCCmec typing showed that most MRSA strains belonged to SCCmec type IV (n = 14; 77.8%). Only 1 (5.56%) MRSA isolates carried the pvl gene. Our findings revealed the relatively high frequency of S aureus nasal carriers and the advent of multidrug resistance among these isolates. Most MRSA isolates were SCCmec type IV; the transfer of such MRSA strains from carriers to other individuals in crowded living conditions such as dormitories can act as a risk factor for outbreak of CA MRSA and is a serious threat for the study groups. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Carriage of Staphylococcus species in the veterinary visiting dog population in mainland UK: molecular characterisation of resistance and virulence.

PubMed

Wedley, Amy L; Dawson, Susan; Maddox, Thomas W; Coyne, Karen P; Pinchbeck, Gina L; Clegg, Peter; Jamrozy, Dorota; Fielder, Mark D; Donovan, David; Nuttall, Tim; Williams, Nicola J

2014-05-14

This study investigated the prevalence of nasal carriage of staphylococci in dogs and determined the characteristics of the isolates. A total of 724 dogs from 87 veterinary practices across the mainland UK were screened for carriage of Staphylococcus spp. All isolates were examined for meticillin resistance (MR) and the presence of the mecA gene investigated in those isolates showing resistance. All coagulase-positive staphylococci and MR coagulase-negative staphylococci (MRCoNS) were subjected to antimicrobial susceptibility testing. Spa typing and DNA microarray analysis of resistance and virulence genes was carried out on all MR S. aureus (MRSA) and a subset of meticillin susceptible S. aureus (MSSA). Staphylococci were isolated from 399 (55.1%) of the dogs; only seven (1%) carried MRSA, all of which were identified as the dominant UK healthcare-associated strain (EMRSA-15, ST22). MSSA was identified in 47 (6.5%) dogs, the sequence types of which have been suggested as precursors to successful MRSA clones. Forty (5.5%) dogs carried MRCoNS, while no dogs carried MR S. pseudintermedius, although this is increasingly reported in mainland Europe. Resistance to antimicrobials among the isolates varied between species, with multidrug resistance (MDR) in 87.5% of MRCoNS and 21.8% of coagulase positive staphylococci. Microarray analysis of MRSA and a subset of MSSA isolates identified numerous virulence genes associated with pathogenesis, which are commonly identified in isolates of human origin. However, no isolates carried Panton-Valentine leukocidin (PVL) genes. This study suggests that MRSA carriage is low in the vet visiting dog population, but there is a diverse range of virulence and resistance determinants in canine S. aureus and MRCoNS isolates. Copyright © 2014 Elsevier B.V. All rights reserved.

Nano-TiO2-based photocatalytic disinfection of environmental surfaces contaminated by meticillin-resistant Staphylococcus aureus.

PubMed

Petti, S; Messano, G A

2016-05-01

Traditional cleaning and disinfection methods are inefficient for complete decontamination of hospital surfaces from meticillin-resistant Staphylococcus aureus (MRSA). Additional methods, such as nano-TiO2-based photocatalytic disinfection (PCD), could be helpful. To evaluate anti-MRSA activity of PCD on polyvinyl chloride (PVC) surfaces in natural-like conditions. Two identical PVC surfaces were used, and nano-TiO2 was incorporated into one of them. The surfaces were contaminated with MRSA isolated from hospitalized patients using a mist sprayer to simulate the mode of environmental contamination caused by a carrier. MRSA cell density was assessed before contamination until 180min after contamination using Rodac plates. The differences between test and control surfaces in terms of MRSA density and log MRSA density reduction were assessed using parametric and non-parametric statistical tests. Five strains were tested, and each strain was tested five times. The highest median MRSA densities [46.3 and 43.1 colony-forming units (cfu)/cm(2) for control and test surfaces, respectively] were detected 45min after contamination. Median MRSA densities 180min after contamination were 10.1 and 0.7cfu/cm(2) for control and test surfaces, respectively (P<0.01). Log MRSA density reduction attributable to PCD was 1.16logcfu/cm(2), corresponding to 93% reduction of the baseline MRSA contamination. The disinfectant activity remained stable throughout the 25 testing occasions, despite between-test cleaning and disinfection. The anti-MRSA activity of PCD was compatible with the benchmark for surface hygiene in hospitals (<1cfu/cm(2)), but required 3h of exposure to photocatalysis. Thus, PCD could be considered for non-clinical surfaces. However, for clinical surfaces, PCD should be regarded as supplemental to conventional decontamination procedures, rather than an alternative. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus.

PubMed

Talia, Juan Manuel; Debattista, Nora Beatriz; Pappano, Nora Beatriz

2011-04-01

Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone - oxacillin. The best combination was 2´,3´-dihydroxychalcone -oxacillin (MIC: 11.2 µg/mL). Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones - oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection.

Potential use of copper surfaces to reduce survival of epidemic meticillin-resistant Staphylococcus aureus in the healthcare environment.

PubMed

Noyce, J O; Michels, H; Keevil, C W

2006-07-01

Epidemic meticillin-resistant Staphylococcus aureus (EMRSA) emerged in the early 1980s with EMRSA-15 and -16 being the most prevalent strains within the UK. MRSA transmission between patients is largely via the hands of healthcare workers, and contamination of the hospital environment may occur. The objective of this study was to evaluate the effectiveness of copper and brass to reduce the viability of air-dried deposits of three MRSA strains [MRSA (NCTC 10442), EMRSA-1 (NCTC 11939) and EMRSA-16 (NCTC 13143)] compared with stainless steel. MRSA and EMRSA [10(7)colony-forming units (CFU)] were inoculated on to coupons (1 cm x 1 cm) of copper, brass or stainless steel and incubated at either 22 degrees C or 4 degrees C for various time periods. Viability was determined by resuspending removed CFUs and plating out on tryptone soy agar plates in addition to staining with the respiratory indicator fluorochrome 5-cyano-2,3-ditolyl tetrazolium. On pure copper surfaces, 10(7) MRSA, EMRSA-1 and EMRSA-16 were completely killed after 45, 60 and 90 min, respectively, at 22 degrees C. In contrast, viable organisms for all three strains were detected on stainless steel (grade 304) after 72 h at 22 degrees C. At 4 degrees C, complete kill was achieved on copper for all three strains within 6 h. The results demonstrate an antimicrobial effect of copper on MRSA, EMRSA-1 and -16 in contrast to stainless steel. Consequently, the contemporary application of stainless steel in hospital environments for work surfaces and door furniture is not recommended.

Increasing antimicrobial resistance in clinical isolates of Staphylococcus intermedius group bacteria and emergence of MRSP in the UK.

PubMed

Beever, L; Bond, R; Graham, P A; Jackson, B; Lloyd, D H; Loeffler, A

2015-02-14

Frequencies of antimicrobial resistance were determined amongst 14,555 clinical Staphylococcus intermedius group (SIG) isolates from UK dogs and cats to estimate resistance trends and quantify the occurrence of meticillin-resistant Staphylococcus pseudintermedius (MRSP). Reports from two diagnostic laboratories (13,313 general submissions, 1242 referral centre only submissions) were analysed retrospectively (2003/2006-2012). MRSP were defined by phenotypic resistance to meticillin and concurrent broad β-lactam resistance; a subset was confirmed genetically (SIG-specific nuc and mecA). Trends were analysed by Cochran-Armitage test. Resistance remained below 10 per cent for cefalexin, amoxicillin-clavulanic acid and the fluoroquinolones. Increasing resistance trends were seen in both laboratories for ampicillin/amoxicillin (both P<0.001), cefovecin (both P<0.046) and enrofloxacin (both P<0.02). Resistance to cefalexin increased over time in referral hospital isolates (P<0.001) to clindamycin (P=0.01) and trimethoprim-sulfamethoxazole (P=0.001) amongst general laboratory submissions. Overall, 106 MRSP were isolated (0.7 per cent of submissions) including 32 (2.6 per cent of submissions, all genetically confirmed) from the referral centre population (inter-laboratory difference P<0.001). Against a background of widely susceptible SIG isolates, a new trend of increasing resistance to important antimicrobials was identified overtime and the emergence of MRSP from UK clinical cases was confirmed. Attention to responsible use of antibacterial therapy in small animal practice is urgently needed. British Veterinary Association.

Distribution of the ACME-arcA gene among meticillin-resistant Staphylococcus haemolyticus and identification of a novel ccr allotype in ACME-arcA-positive isolates.

PubMed

Pi, Borui; Yu, Meihong; Chen, Yagang; Yu, Yunsong; Li, Lanjuan

2009-06-01

The aim of this study was to investigate the prevalence and characteristics of ACME (arginine catabolic mobile element)-arcA-positive isolates among meticillin-resistant Staphylococcus haemolyticus (MRSH). ACME-arcA, native arcA and SCCmec elements were detected by PCR. Susceptibilities to 10 antimicrobial agents were compared between ACME-arcA-positive and -negative isolates by chi-square test. PFGE was used to investigate the clonal relatedness of ACME-arcA-positive isolates. The phylogenetic relationships of ACME-arcA and native arcA were analysed using the neighbour-joining methods of mega software. A total of 42 (47.7 %) of 88 isolates distributed in 13 PFGE types were positive for the ACME-arcA gene. There were no significant differences in antimicrobial susceptibility between ACME-arcA-positive and -negative isolates. A novel ccr allotype (ccrAB(SHP)) was identified in ACME-arcA-positive isolates. Among 42 ACME-arcA-positive isolates: 8 isolates harboured SCCmec V, 8 isolates harboured class C1 mec complex and ccrAB(SHP); 22 isolates harbouring class C1 mec complex and 4 isolates harbouring class C2 mec complex were negative for all known ccr allotypes. The ACME-arcA-positive isolates were first found in MRSH with high prevalence and clonal diversity, which suggests a mobility of ACME within MRSH. The results from this study revealed that MRSH is likely to be one of the potential reservoirs of ACME for Staphylococcus aureus.

Molecular characteristics of methicillin-resistant Staphylococcus aureus nasal carriage from hospitalized patients and medical staff in Isfahan, Iran.

PubMed

Moshtagheian, S; Halaji, M; Sedaghat, H; Shahin, M; Esfahani, B N; Havaei, S R; Havaei, S A

2018-01-01

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) has been accounted as one of the main risk factors for the development of complicated nosocomial infections. The present study aimed to determine nasal carriage rate, antimicrobial susceptibility pattern and molecular characteristics of MRSA isolates. This cross-sectional study was performed within 6 months period from July 2015 at 3 hospitals of Isfahan, Iran. Totally, 326 nasal samples were collected by cotton sterile swab from the nasal cavity of participants. Standard microbiological methods were used for identification S. aurues and MRSA isolates. Antibiotic susceptibility pattern was determined by the disc diffusion method according to the CLSI recommendation. Determination of SCCmec typing, agr groups, and virulence genes were performed by PCR method. Overall, 23.6% of cases were S. aureus carriers including, 23.4% (25/107) of HCWs and 23.7% (52/219) of patients. The rate of MRSA nasal carriages among patients was found to be 51.9% and 16% in HCWs. The highest levels of resistance among MRSA isolates were against ampicillin (93.5%) and tetracycline (83.4%); while, the most effective antibiotics were vancomycin and co-trimoxazole with 100% and 71%, susceptibility. The presence of hla and pvl genes was detected in 80.6% and 3.2% of MRSA isolates, respectively. SCCmec types I, III, IV and V were found in 16.1%, 25.8%, 25.8%, and 16.1% of isolates, respectively. Moreover, agr group I was the predominant type with 43.3. Our results showed a high rate of MRSA colonization in hospitalized patients which remains a significant healthcare problem in our region.

Livestock-Associated, Antibiotic-Resistant Staphylococcus aureus Nasal Carriage and Recent Skin and Soft Tissue Infection among Industrial Hog Operation Workers

PubMed Central

Nadimpalli, Maya; Stewart, Jill R.; Pierce, Elizabeth; Pisanic, Nora; Love, David C.; Hall, Devon; Larsen, Jesper; Carroll, Karen C.; Tekle, Tsigereda; Perl, Trish M.

2016-01-01

Swine production work is a risk factor for nasal carriage of livestock-associated (LA-) Staphylococcus aureus and also for skin and soft tissue infection (SSTI). However, whether LA-S. aureus nasal carriage is associated with increased risk of SSTI remains unclear. We aimed to examine S. aureus nasal carriage and recent (≤3 months prior to enrollment) SSTI symptoms among industrial hog operation (IHO) workers and their household contacts. IHO workers and their household contacts provided a nasal swab and responded to a questionnaire assessing self-reported personal and occupational exposures and recent SSTI symptoms. Nasal swabs were analyzed for S. aureus, including methicillin-resistant S. aureus (MRSA), multidrug-resistant-S. aureus (MDRSA), absence of scn (livestock association), and spa type. S. aureus with at least one indicator of LA was observed among 19% of 103 IHO workers and 6% of 80 household members. Prevalence of recent SSTI was 6% among IHO workers and 11% among 54 minor household members (0/26 adult household members reported SSTI). Among IHO workers, nasal carriers of MDRSA and scn-negative S. aureus were 8.8 (95% CI: 1.8, 43.9) and 5.1 (95% CI: 1.2, 22.2) times as likely to report recent SSTI as non-carriers, respectively. In one household, both an IHO worker and child reported recent SSTI and carried the same S. aureus spa type (t4976) intranasally. Prevalence of scn-negative S. aureus (PR: 5.0, 95% CI: 1.2, 21.4) was elevated among IHO workers who reported never versus always wearing a face mask at work. Although few SSTI were reported, this study of IHO workers and their household contacts is the first to characterize a relation between nasal carriage of antibiotic-resistant LA-S. aureus and SSTI. The direction and temporality of this relation and IHO workers’ use of face masks to prevent nasal carriage of these bacteria warrant further investigation. PMID:27851746

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus

PubMed Central

Talia, Juan Manuel; Debattista, Nora Beatriz; Pappano, Nora Beatriz

2011-01-01

Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone – oxacillin. The best combination was 2´,3´-dihydroxychalcone -oxacillin (MIC: 11.2 µg/mL). Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones – oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection. PMID:24031657

Rapid detection of meticillin-resistant Staphylococcus aureus bacteraemia using combined three-hour short-incubation matrix-assisted laser desorption/ionization time-of-flight MS identification and Alere Culture Colony PBP2a detection test.

PubMed

Delport, Johannes Andries; Mohorovic, Ivor; Burn, Sandi; McCormick, John Kenneth; Schaus, David; Lannigan, Robert; John, Michael

2016-07-01

Meticillin-resistant Staphylococcus aureus (MRSA) bloodstream infection is responsible for significant morbidity, with mortality rates as high as 60 % if not treated appropriately. We describe a rapid method to detect MRSA in blood cultures using a combined three-hour short-incubation BRUKER matrix-assisted laser desorption/ionization time-of-flight MS BioTyper protocol and a qualitative immunochromatographic assay, the Alere Culture Colony Test PBP2a detection test. We compared this combined method with a molecular method detecting the nuc and mecA genes currently performed in our laboratory. One hundred and seventeen S. aureus blood cultures were tested of which 35 were MRSA and 82 were meticillin-sensitive S. aureus (MSSA). The rapid combined test correctly identified 100 % (82/82) of the MSSA and 85.7 % (30/35) of the MRSA after 3 h. There were five false negative results where the isolates were correctly identified as S. aureus, but PBP2a was not detected by the Culture Colony Test. The combined method has a sensitivity of 87.5 %, specificity of 100 %, a positive predictive value of 100 % and a negative predictive value of 94.3 % with the prevalence of MRSA in our S. aureus blood cultures. The combined rapid method offers a significant benefit to early detection of MRSA in positive blood cultures.

The Prevalence of Antibiotic-Resistant Staphylococcus aureus Nasal Carriage among Industrial Hog Operation Workers, Community Residents, and Children Living in Their Households: North Carolina, USA

PubMed Central

Hatcher, Sarah M.; Rhodes, Sarah M.; Stewart, Jill R.; Silbergeld, Ellen; Pisanic, Nora; Larsen, Jesper; Jiang, Sharon; Krosche, Amanda; Hall, Devon; Carroll, Karen C.; Heaney, Christopher D.

2016-01-01

Background: Antibiotic use in industrial hog operations (IHOs) can support the emergence of antibiotic-resistant (ABR) Staphylococcus aureus. The extent of ABR S. aureus exposure in IHO workers and children living in their households remains unclear. Objective: We investigated ABR S. aureus nasal carriage prevalence among adults with versus without occupational exposure to IHOs and among children living in their households. Methods: In total, 198 IHO worker–child household pairs and 202 community referent (CR) adult–child household pairs completed a questionnaire and provided a nasal swab which was analyzed for S. aureus, methicillin-resistant S. aureus (MRSA), multidrug-resistant S. aureus (MDRSA), absence of scn (putative marker of livestock association), and spa type. Results: S. aureus nasal carriage prevalence was higher among IHO (53%) compared with CR (31%) adults [adjusted prevalence ratio (aPR): 1.40; 95% confidence interval (CI): 1.07, 1.83], but MRSA nasal carriage prevalence was uncommon (2–3%) in IHO and CR adults. MDRSA nasal carriage prevalence was similar among IHO workers and CR adults (12% vs. 8%; aPR: 1.14; 95% CI: 0.56, 2.29). Nasal carriage prevalence was higher among IHO compared with CR children for S. aureus (49% vs. 31%; aPR: 1.50; 95% CI: 1.13, 1.99), MRSA (14% vs. 6%; aPR: 2.37; 95% CI: 1.14, 4.92), and MDRSA (23% vs. 8%; aPR: 2.64; 95% CI: 1.47, 4.75). We also found suggestive evidence of a higher prevalence of S. aureus, MRSA, and MDRSA among children living with an IHO worker who did versus did not report taking personal protective equipment (PPE) home from the IHO. Livestock-associated S. aureus nasal carriage predominated among IHO workers. Conclusion: Our findings support the importance of further research on the prevalence and potential sources of exposure to ABR S. aureus among children living with IHO workers. Citation: Hatcher SM, Rhodes SM, Stewart JR, Silbergeld E, Pisanic N, Larsen J, Jiang S, Krosche A, Hall D, Carroll

Nasal carriage of Staphylococcus aureus in Australian (pre-clinical and clinical) medical students.

PubMed

Stubbs, E; Pegler, M; Vickery, A; Harbour, C

1994-06-01

The nasal carriage of Staphylococcus aureus in 808 Australian medical students was studied. Five groups of students experienced varying degrees of clinical exposure in a hospital environment ranging from 0 to 42 months. The overall percentage of carriers among the five groups did not vary. However, with increasing clinical exposure there was a decrease in the percentage of isolates sensitive to all antibiotics tested, and an increase in the carriage of S. aureus resistant to three or more antibiotics. No carriers of methicillin-resistant S. aureus (MRSA) were detected. The comparative rates of S. aureus carriage between female and male students varied. The relevance of medical students as nasal carriers of S. aureus in the hospital environment today is discussed.

Methicillin-resistant Staphylococcus aureus nasal carriage among primary school-aged children from Jordan: prevalence, antibiotic resistance and molecular characteristics.

PubMed

Alzoubi, Hamed M; Aqel, Amin A; Al-Sarayreh, Sameeh A; Al-Zayadneh, Enas

2014-12-01

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) increases the risk for subsequent infections with an increased mortality and morbidity. Children were suggested to be a major asymptomatic reservoir for community-associated (CA) MRSA with an ability to quickly spread the MRSA within community. Therefore, the availability of epidemiological and antibiotic susceptibility data of CA-MRSA will be useful for the infection control and management policies. This study aimed to assess the nasal carriage, molecular characteristics and antibiotic susceptibility of MRSA in primary school-aged children from Jordan. A total of 210 nasal swabs were collected from children aged 6-11 years. Isolated MRSA and its SCCmec typing, Spa type and PVL (Panton-Valentine Leukociden) toxin were identified following culture, biochemical and PCR. Antibiogram was determined by the disc diffusion method. The prevalence of CA-MRSA was 7.1%. Allergic rhinitis and recent antibiotic exposure were the only significant risk factors for MRSA nasal carriage among children. Resistance to erythromycin, trimethoprim-sulfamethoxazole and tetracycline was 33.4, 20 and 13.4%, respectively. All isolates were susceptible to the remaining non-β-lactam antibiotics used in this study, in particular linezolid and mupirocin. All MRSA isolates were SCCmec type IV and PVL toxin negative and the majority were Spa type t223. This is the first study to assess the MRSA prevalence among children aged 6-11 years in Jordan. The prevalence in community children is within the range compared with other studies in other countries. The antibiogram, SCCmec and Spa types of the isolated MRSA are much similar to what was found previously in Jordan. However, all isolates were PVL toxin negative. The study recommends increasing the public awareness of MRSA and the proper antibiotics dispensing. Future studies to follow-up on the changing epidemiology of the CA-MRSA in Jordan are also recommended.

Natural and ion-exchanged illite clays reduce bacterial burden and inflammation in cutaneous meticillin-resistant Staphylococcus aureus infections in mice

PubMed Central

Otto, Caitlin C.; Kilbourne, Jacquelyn

2016-01-01

Discoveries associated with antibacterial activity of hydrated clays necessitate assessments of in vivo efficacy, practical use and safety. Surface properties of clays can lead to variations in the composition and abundance of bound compounds or ions, thus affecting antibacterial activity. Since exchangeable metal ions released from the clay surface are responsible for in vitro antibacterial activity, we evaluated the in vivo antibacterial efficacy of four natural clays (one illite clay, two montmorillonite clays and one kaolinite clay) and three ion-exchanged, antibacterial clays against superficial, cutaneous meticillin-resistant Staphylococcus aureus (MRSA) infections in mice. Superficial, cutaneous wounds on the back of SKH1-Elite mice were generated and subsequently infected with MRSA. Following twice daily applications of a hydrated clay poultice to infected wounds for 7 days, we observed significant differences in the in vivo antibacterial efficacy between different types of clays. The natural and ion-exchanged illite clays performed best, as measured by bacterial load, inflammatory response and gross wound morphology with significant decreases in bacterial viability and dermatitis. Topical application of kaolinite clay was the least effective, resulting in the lowest decrease in bacterial load and exhibiting severe dermatitis. These data suggest that specific types of clays may offer a complementary and integrative strategy for topically treating MRSA and other cutaneous infections. However, since natural clays exhibit in vitro antibacterial variability and vary vastly in surface chemistries, adsorptive/absorptive characteristics and structural composition, the properties and characteristics of illite clays could aid in the development of standardized and customized aluminosilicates for topical infections. PMID:26508716

Nasal carriage of Methicillin- and Mupirocin-resistant S. aureus among health care workers in a tertiary care hospital.

PubMed

Agarwal, Loveleena; Singh, Amit Kumar; Sengupta, Chandrim; Agarwal, Amitabh

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) ranks top among the nosocomial pathogens. Nasal formulation of mupirocin is found to eradicate MRSA from colonized individuals, but the emergence of resistant strains is a matter of concern. Nasal swabs were collected from 200 health care workers (HCWs) who were screened for MRSA. Kirby-Bauer disc diffusion method was used to perform antibiotic susceptibility test. MRSA detection was done using a cefoxitin 30 µg disc and interpreted according to the Clinical and Laboratory Standards Institute guidelines. Determination of mupirocin resistance was performed using Epsilometer test (E-test). About 14% of HCWs showed nasal carriage of MRSA. Nursing orderlies were the predominant carriers. E-test showed four mupirocin resistant isolates. The antibiogram of the MRSA isolates revealed the higher resistance to antibiotics as compared to methicillin-sensitive Staphylococcus aureus. All the MRSA isolates were sensitive to linezolid. HCWs in our hospital showed high nasal carriage rate of MRSA, particularly the nursing orderlies which is statistically significant. It is advisable to detect mupirocin resistance among the isolates obtained from the HCWs so that in case of resistance, alternative treatment should be sought.

Prevalence and risk factors for Staphylococcus aureus and methicillin-resistant Staphylococcus aureus nasal carriage inpatients in a tertiary care hospital's chest clinic in Turkey.

PubMed

Oguzkaya-Artan, M; Artan, C; Baykan, Z

2016-01-01

We aimed to determine the prevalence and associated risk factors for nasal methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA/MRSA) carriage among patients admitted to a chest clinic of a tertiary care hospital in this study. Nasal samples were taken from anterior nares were cultured in CHROMagar S. aureus plates, MRSA was determined by disc diffusion method (cefoxitin 30 μg) according to the Clinical and Laboratory Standards Institute guidelines and CHROMagar MRSA plates. A questionnaire was applied to determine the demographic characteristics of the participants and risk factors for carriage. Fisher's exact test, univariate and multivariate logistic regression analysis were used. A P < 0.05 indicated a statistically significant difference. This is a cross-sectional study covering all the patients (n = 431) admitted to Kayseri Training and Research Hospital's Chest Clinic from January 1st to 31st 2014. Of all these patients 55 (12.8%) were nasal S. aureus carriers. MRSA positivity was in five among these patients. In multivariate analysis, being under 65 years of age (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.0-3.3), and having prosthesis (OR, 4.8; 95% CI, 1.6-13.9) were found as risk factors for MSSA colonization. The prevalence of nasal carriage of MSSA was low in our study population. The only risk factors playing role in carriage were found as being under the age of 65 and having prosthesis.

A systematic review of the evidence for interventions for the prevention and control of meticillin-resistant Staphylococcus aureus (1996-2004): report to the Joint MRSA Working Party (Subgroup A).

PubMed

Loveday, H P; Pellowe, C M; Jones, S R L J; Pratt, R J

2006-05-01

A systematic review was undertaken of the evidence published between 1996 and 2004 on the effectiveness, and associated economic costs, of a range of interventions to prevent and control the transmission of meticillin-resistant Staphylococcus aureus (MRSA) in hospital settings. The review questions focused on screening, patient isolation, use of decolonization strategies, feedback of surveillance data, and environmental hygiene interventions. The reviewers assessed evidence from four recent systematic reviews, 24 non-experimental descriptive studies, five economic evaluations and one recently revised international guideline. The methodological quality of studies retrieved was such that there is currently insufficient high-quality evidence for infection prevention and control interventions in the fields identified for this review. However, evidence from clinically based, non-experimental studies does provide support for the continued use of a range and combination of interventions that contribute to the prevention and control of MRSA within acute hospitals and long-term-care settings. Well-conducted economic evaluations reporting the economic benefits arising from infection prevention and control interventions are lacking.

Sustained meticillin-resistant Staphylococcus aureus control in a hyper-endemic tertiary acute care hospital with infrastructure challenges in Singapore.

PubMed

Fisher, D; Tambyah, P A; Lin, R T P; Jureen, R; Cook, A R; Lim, A; Ong, B; Balm, M; Ng, T M; Hsu, L Y

2013-10-01

Meticillin-resistant Staphylococcus aureus (MRSA) has been entrenched in Singapore hospitals since the 1980s, with an excess of 600 non-duplicate cases of infections (120 bacteraemia episodes) each year in our 995-bed university hospital. Approximately 5% of our hospital beds are used as isolation facilities. To study the impact of an MRSA control bundle that was implemented via gradual geographic extension across hospital wards. The bundle included active surveillance on admission and transfer/discharge to identify ward-based acquisition of MRSA, isolation and cohorting of MRSA-infected patients, enhanced hand hygiene initiatives, and publicly displayed feedback of MRSA acquisition and hand hygiene compliance rates. Implementation was between October 2006 and June 2010 in order to provide lead-time for the incremental development of infrastructural capacity, and to develop an ethic of infection prevention among staff. Results were analysed via interrupted time-series analysis. MRSA infections fell midway through the implementation, with MRSA bacteraemia declining from 0.26 [95% confidence interval (CI): 0.18-0.34] cases per 1000 inpatient-days in the first quarter of 2004 to 0.11 (95% CI: 0.07-0.19) cases per 1000 inpatient-days in the first quarter of 2012. MRSA acquisition rates fell a year after the programme had been fully implemented, whereas hand hygiene compliance rose significantly from 47% (95% CI: 44-49) in the first quarter of 2009 to 69% (95% CI: 68-71) in the first quarter of 2012. Successful staged implementation of an MRSA bundle in a hyper-endemic setting is sustainable and represents a model that may be adapted for similar settings. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Methicillin-resistant Staphylococcus aureus nasal colonisation amongst healthcare workers in Kurdistan Region, Iraq.

PubMed

Hussein, Nawfal R; Assafi, Mahde S; Ijaz, Tayyaba

2017-06-01

The aim of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) compared with non-HCWs at Duhok city, Kurdistan Region, northern Iraq. A total of 182 HCWs with different occupations and working in different hospital units as well as 198 non-HCWs were recruited. Nasal swab samples were collected and were inoculated on mannitol salt agar and incubated at 35°C for 48h. Isolates identified as S. aureus underwent antimicrobial sensitivity testing to oxacillin. MRSA isolates were selected and investigated for presence of the mecA gene. Among the HCWs, 41/182 (22.5%) were carriers of S. aureus compared with 37/198 (18.7%) non-HCWs (P=0.4). Amongst the S. aureus carriers, 25/41 strains (61.0%) isolated from HCWs were MRSA compared with 8/37 strains (21.6%) isolated from non-HCWs (P=0.039). The mean age of MRSA carriers was 35.6±6.7years compared with 30±5.8years for MRSA non-carriers (P=0.0177). The mean working years of MRSA carriers was significantly higher than that of MRSA non-carriers (7.8±5.5years vs. 3.9±5.3years; P=0.04). The prevalence of MRSA was very high amongst HCWs. Regular screening of carriers is required for prevention of nosocomial infections. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

The Effectiveness of Bacteriophages against Methicillin-Resistant Staphylococcus aureus ST398 Nasal Colonization in Pigs.

PubMed

Verstappen, Koen M; Tulinski, Pawel; Duim, Birgitta; Fluit, Ad C; Carney, Jennifer; van Nes, Arie; Wagenaar, Jaap A

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential approach for the control of MRSA colonization to minimize the-often occupational-exposure of humans. The aim of this study was to assess the efficacy of bacteriophage treatment on porcine nasal colonization with MRSA in vitro, in vivo, and ex vivo. The effectiveness of a bacteriophage combination of phage K*710 and P68 was assessed in vitro by incubating them with MRSA V0608892/1 (ST398) measuring the OD600 hourly. To study the in vivo effect, bacteriophages were administered in a gel developed for human application, which contain 109 plaque-forming units (pfu)/mL (K and P68 in a 19.25:1 ratio) for 5 days to piglets (N = 8) that were experimentally colonized with the MRSA strain. Eight piglets experimentally colonized were used as a negative control. The MRSA strain was also used to colonize porcine nasal mucosa explants and bacteriophages were applied to assess the ex vivo efficacy of treatment. Bacteriophages were effective in vitro. In vivo, sixteen piglets were colonized with MRSA but the number of CFU recovered after the application of the bacteriophages in 8 piglets was not reduced compared to the control animals (approx. 105 CFU/swab). In the ex vivo model, 108 CFU were used to establish colonization with MRSA; a reduction of colonization was not observed after application of bacteriophages. However, application of mupirocin both in vivo and ex vivo resulted in a near eradication of MRSA. i) The MRSA strain was killed in the presence of the bacteriophages phage K*710 and P68 in vitro. ii) Bacteriophages did not reduce porcine nasal colonization in vivo or ex vivo. Physiological in vivo and ex vivo conditions may explain these observations. Efficacy in the ex vivo

The Effectiveness of Bacteriophages against Methicillin-Resistant Staphylococcus aureus ST398 Nasal Colonization in Pigs

PubMed Central

Duim, Birgitta; Fluit, Ad C; Carney, Jennifer; van Nes, Arie; Wagenaar, Jaap A

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential approach for the control of MRSA colonization to minimize the—often occupational—exposure of humans. The aim of this study was to assess the efficacy of bacteriophage treatment on porcine nasal colonization with MRSA in vitro, in vivo, and ex vivo. The effectiveness of a bacteriophage combination of phage K*710 and P68 was assessed in vitro by incubating them with MRSA V0608892/1 (ST398) measuring the OD600 hourly. To study the in vivo effect, bacteriophages were administered in a gel developed for human application, which contain 109 plaque-forming units (pfu)/mL (K and P68 in a 19.25:1 ratio) for 5 days to piglets (N = 8) that were experimentally colonized with the MRSA strain. Eight piglets experimentally colonized were used as a negative control. The MRSA strain was also used to colonize porcine nasal mucosa explants and bacteriophages were applied to assess the ex vivo efficacy of treatment. Bacteriophages were effective in vitro. In vivo, sixteen piglets were colonized with MRSA but the number of CFU recovered after the application of the bacteriophages in 8 piglets was not reduced compared to the control animals (approx. 105 CFU/swab). In the ex vivo model, 108 CFU were used to establish colonization with MRSA; a reduction of colonization was not observed after application of bacteriophages. However, application of mupirocin both in vivo and ex vivo resulted in a near eradication of MRSA. In conclusion: i) The MRSA strain was killed in the presence of the bacteriophages phage K*710 and P68 in vitro. ii) Bacteriophages did not reduce porcine nasal colonization in vivo or ex vivo. Physiological in vivo and ex vivo conditions may explain these observations. Efficacy

Triclosan Promotes Staphylococcus aureus Nasal Colonization

PubMed Central

Syed, Adnan K.; Ghosh, Sudeshna; Love, Nancy G.; Boles, Blaise R.

2014-01-01

ABSTRACT The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. PMID:24713325

Utility of nasal swab and age in detecting methicillin-resistant Staphylococcus aureus in pediatric head and neck abscesses.

PubMed

Bradford, Benjamin D; Macias, David; Liu, Yuan F; Inman, Jared C; Dyleski, Robin A

2017-10-01

To identify risk factors associated with the presence of methicillin-resistant Staphylococcus aureus (MRSA) in surgical cultures taken from incision and drainage (I&D) of head and neck abscesses in the pediatric population. Retrospective case series. All patients under 18 years of age with a head and neck abscess requiring I&D from 2009 to 2015 were reviewed. MRSA nasal swab cultures were taken from all patients upon hospitalization. Surgical cultures were obtained from all patients and correlated with MRSA nasal swab results. Univariate and multivariate logistic regression was performed, and odds ratios (ORs) along with descriptive statistics were analyzed. Of a total of 272 patients, there were 68 (25%) MRSA-positive abscesses. The majority (86.8%) of these abscesses were in children under 2 years of age. Overall, 12 (4.4%) presented with positive admission MRSA nasal swabs. Of these, 91.7% had MRSA-positive abscess cultures. Decreasing age in years showed an OR of 1.650 (P < 0.001) for MRSA-positive abscess, with children less than 1 year old having the highest OR of 10.74 (P < 0.001). Younger age and MRSA nasal colonization were two statistically significant risk factors for developing an MRSA abscess of the head and neck. This study demonstrates a high positive predictive value for MRSA-positive neck abscesses when nasal swab screenings were MRSA-positive (91.7%). Children under 2 years of age-especially those under 1 year of age-or those with MRSA nasal colonization can be considered a high-risk population that may benefit from empiric antibiotics against MRSA for head and neck abscesses. 4. Laryngoscope, 127:2407-2412, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Methicillin-resistant Staphylococcus aureus in a neonatal alpaca

PubMed Central

Stull, Jason W.; Kenney, Daniel G.; Slavić, Durda; Weese, J. Scott

2012-01-01

A 6-hour-old alpaca was presented for evaluation of respiratory difficulty. As part of routine surveillance, methicillin-resistant Staphylococcus aureus (MRSA) was identified from a nasal swab taken upon admission to the hospital. No signs of MRSA infection were noted. The MRSA strain recovered was a human epidemic clone that has been associated with horses. Methicillin-resistant S. aureus colonization can occur in camelids, and the potential animal and public health risks require consideration. PMID:23204589

Risk factors for development of methicillin-resistant Staphylococcus aureus-positive clinical culture in nasal carriers after decolonization treatment.

PubMed

Hernández-Porto, Miriam; Castro, Beatriz; Ramos, Maria Jose; Arias, Angeles; Aguirre-Jaime, Armando; Lecuona, Maria

2014-07-01

Active surveillance systems are effective in reducing health care-associated infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Nonetheless, some patients develop MRSA infection despite control measures. We tried to identify risk factors related to the appearance of MRSA at sites other than the nasal fossa in patients who were nasal carriers of MRSA. A retrospective case-control study was conducted in an active surveillance program for MRSA between January 2009 and December 2010 at a Spanish teaching hospital. Cases were patients with MRSA in the anterior nares and a length of stay of at least 5 days who developed MRSA-positive clinical culture after decolonization treatment had started. Controls were patients with the same characteristics as the case group, except that they did not develop MRSA-positive clinical culture as verified by negative clinical cultures. After intrinsic and extrinsic risk factors were analyzed, the emergence of mupirocin-resistant MRSA clones after decolonization treatment, and residence in a nursing home were marginally significant in the univariate analysis. The detection of the emergence of mupirocin-resistant MRSA clones was independently associated with the detection of MRSA in other clinical locations. In an active surveillance program for MRSA it is important to determine the mupirocin susceptibility of the isolates to determine appropriate treatment and to verify negativity after decolonizing treatment has been completed. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Vitamin E improves the in vivo efficacy of tigecycline and daptomycin in an animal model of wounds infected with meticillin-resistant Staphylococcus aureus.

PubMed

Provinciali, Mauro; Cirioni, Oscar; Orlando, Fiorenza; Pierpaoli, Elisa; Barucca, Alessandra; Silvestri, Carmela; Ghiselli, Roberto; Scalise, Alessandro; Brescini, Lucia; Guerrieri, Mario; Giacometti, Andrea

2011-12-01

A relevant bacterial load in cutaneous wounds significantly interferes with the normal process of healing. Vitamin E (VE) is a known immunomodulator and immune enhancer. Here, it was shown that administration of VE before infection was effective at increasing the antimicrobial activity of daptomycin (DAP) or tigecycline (TIG) in a mouse model of wound infection caused by meticillin-resistant Staphylococcus aureus (MRSA). A wound was established through the panniculus carnosus of mice and inoculated with MRSA. Mice were assigned to six groups: a VE pre-treated group with no antibiotics given after MRSA challenge; two VE pre-treated groups with DAP or TIG given after MRSA challenge; two groups treated with DAP or TIG only after MRSA challenge; and a control group that did not receive any treatment. Mice receiving each antibiotic alone showed a 3 log decrease in the number of c.f.u. recovered compared with the control group, mice treated with VE plus TIG had a 4 log decrease, whilst mice treated with VE plus DAP had the largest decrease in c.f.u. recovered (5 logs). The increased antimicrobial effect seen from treatment with VE plus antibiotics was associated with increased levels of natural killer cell cytotoxicity, with a more pronounced increase in leukocyte populations in mice treated with VE plus DAP. These data suggest that treatment with VE prior to infection and subsequent antibiotic treatment act in synergy. © 2011 SGM

Performance of the cobas MRSA/SA Test for Simultaneous Detection of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus From Nasal Swabs.

PubMed

Peterson, Lance R; Woods, Christopher W; Davis, Thomas E; Wang, Zi-Xuam; Young, Stephen A; Osiecki, John C; Lewinski, Michael A; Liesenfeld, Oliver

2017-08-01

Health care-associated methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (SA) infections are continuing problems. Rapidly determining the MRSA colonization status of a patient facilitates practice to reduce spread of MRSA clinical disease. Sensitive detection of all SA prior to surgery, followed by decolonization, can significantly reduce postoperative infection from this pathogen. Our goal was to validate a new automated assay for this testing. We compared performance of the cobas MRSA/SA Test on the cobas 4800 System to direct and enriched chromogenic culture using nasal swabs collected from patients at six United States sites. Compared to direct and enriched culture, the sensitivity for MRSA and SA was 93.1% and 93.9%, and the specificity was 97.5% and 94.2%, respectively. After discrepancy analysis, the sensitivity for MRSA and SA was 97.1% and 98.6%, and the specificity was 98.3% and 95.5%, respectively. Compared to direct culture, sensitivity for detecting any SA was 99.6%. The cobas MRSA/SA Test is an effective tool to simultaneously perform surveillance testing for nasal colonization of both MRSA and MSSA. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Low prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in urban and rural community settings in Bolivia and Peru.

PubMed

Bartoloni, Alessandro; Pallecchi, Lucia; Fernandez, Connie; Mantella, Antonia; Riccobono, Eleonora; Magnelli, Donata; Mannini, Dario; Strohmeyer, Marianne; Bartalesi, Filippo; Segundo, Higinio; Monasterio, Joaquin; Rodriguez, Hugo; Cabezas, César; Gotuzzo, Eduardo; Rossolini, Gian Maria

2013-05-01

To investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in rural and urban community settings of Bolivia and Peru. MRSA nasal carriage was investigated in 585 individuals living in rural and urban areas of Bolivia and Peru (one urban area, one small rural village, and two native communities, one of which was highly isolated). MRSA isolates were subjected to molecular analysis for the detection of virulence genes, characterization of the staphylococcal cassette chromosome mec (SCCmec), and genotyping (multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)). An overall very low prevalence of MRSA nasal carriage was observed (0.5%), with MRSA carriers being detected only in a small rural village of the Bolivian Chaco. The three MRSA isolates showed the characteristics of community-associated MRSA (being susceptible to all non-beta-lactam antibiotics and harboring the SCCmec type IV), were clonally related, and belonged to ST1649. This study provides an insight into the epidemiology of MRSA in community settings of Bolivia and Peru. Reliable, time-saving, and low-cost methods should be implemented to encourage continued surveillance of MRSA dissemination in resource-limited countries. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Clinical utility of methicillin-resistant Staphylococcus aureus nasal polymerase chain reaction assay in critically ill patients with nosocomial pneumonia.

PubMed

Smith, Melanie N; Erdman, Michael J; Ferreira, Jason A; Aldridge, Petra; Jankowski, Christopher A

2017-04-01

This study investigated the diagnostic performance characteristics of a methicillin-resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) assay in critically ill patients with nosocomial pneumonia. This retrospective, single-center study included adult patients admitted to an intensive care unit with suspected nosocomial pneumonia. Patients must have received an MRSA nasal PCR assay and respiratory culture within predetermined time intervals. The primary outcome included the diagnostic performance characteristics of the assay. Secondary outcomes included the change in negative predictive value (NPV) over time, rate of acute kidney injury, and cost avoidance associated with vancomycin and monitoring. In 400 patients meeting inclusion criteria, the prevalence of culture confirmed MRSA pneumonia was 9.3%. When compared to initial cultures, the PCR assay demonstrated 91.89% sensitivity and 84.3% specificity with a positive predictive value and NPV of 37.36% and 99.03%. The NPV decreased to 87.5% at 21.9 days. No difference was found in rates of acute kidney injury. A cost avoidance of $108 per patient was estimated in patients de-escalated based on negative results. In critically ill patients, an MRSA nasal PCR assay has a high NPV for nosocomial pneumonia and can be used to guide vancomycin de-escalation. Copyright © 2016 Elsevier Inc. All rights reserved.

A multicentre study of meticillin-resistant Staphylococcus aureus in acute bacterial skin and skin-structure infections in China: susceptibility to ceftaroline and molecular epidemiology.

PubMed

Zhang, Hui; Xiao, Meng; Kong, Fanrong; O'Sullivan, Matthew V N; Mao, Lei-Li; Zhao, Hao-Ran; Zhao, Ying; Wang, He; Xu, Ying-Chun

2015-04-01

Ceftaroline is a novel cephalosporin with activity against Gram-positive organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The objective of this study was to investigate the susceptibility to ceftaroline of hospital-associated MRSA (HA-MRSA) isolates causing acute bacterial skin and skin-structure infections (ABSSSIs) in China and to examine their relationship by genotyping. A total of 251 HA-MRSA isolates causing ABSSSIs were collected from a multicentre study involving 56 hospitals in 38 large cities across 26 provinces in mainland China. All isolates were characterised by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, spa typing and detection of the Panton-Valentine leukocidin locus (lukS-PV and lukF-PV). Minimum inhibitory concentrations (MICs) of 14 antimicrobial agents, including ceftaroline, were determined by broth microdilution and were interpreted using Clinical and Laboratory Standards Institute breakpoints. The ceftaroline MIC50 and MIC90 values (MICs that inhibit 50% and 90% of the isolates, respectively) were 1 μg/mL and 2 μg/mL, respectively; 33.5% (n=84) of the isolates studied were ceftaroline-non-susceptible, with MICs of 2 μg/mL, but no isolate exhibited ceftaroline resistance (MIC>2 μg/mL). All of the ceftaroline-non-susceptible isolates belonged to the predominant HA-MRSA clones: 95.2% (n=80) from MLST clonal complex 8 (CC8), with the remaining 4.8% (n=4) from CC5. The high rate of non-susceptibility to ceftaroline amongst HA-MRSA causing ABSSSIs in China is concerning. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Escherichia coli and Staphylococcus aureus: bad news and good news from the European Antimicrobial Resistance Surveillance Network (EARS-Net, formerly EARSS), 2002 to 2009.

PubMed

Gagliotti, C; Balode, A; Baquero, F; Degener, J; Grundmann, H; Gür, D; Jarlier, V; Kahlmeter, G; Monen, J; Monnet, D L; Rossolini, G M; Suetens, C; Weist, K; Heuer, O

2011-03-17

Based on data collected by the European Antimicrobial Resistance Surveillance Network (EARS-Net) and the former EARSS, the present study describes the trends in antimicrobial susceptibility patterns and occurrence of invasive infections caused by Escherichia coli and Staphylococcus aureus in the period from 2002 to 2009. Antimicrobial susceptibility results from 198 laboratories in 22 European countries reporting continuously on these two microorganisms during the entire study period were included in the analysis. The number of bloodstream infections caused by E. coli increased remarkably by 71% during the study period, while bloodstream infections caused by S. aureus increased by 34%. At the same time, an alarming increase of antimicrobial resistance in E. coli was observed, whereas for S. aureus the proportion of meticillin resistant isolates decreased. The observed trend suggests an increasing burden of disease caused by E. coli. The reduction in the proportion of meticillin-resistant S. aureus and the lesser increase in S. aureus infections, compared with E. coli, may reflect the success of infection control measures at hospital level in several European countries.

Multidrug-resistant Staphylococcus haemolyticus isolates from infected eyes and healthy conjunctivae in India.

PubMed

Panda, Sasmita; Kar, Sarita; Sharma, Savitri; Singh, Durg V

2016-09-01

This study aimed to determine the presence of antibiotic resistance genes (ARGs), SCCmec elements and genetic relatedness among Staphylococcus haemolyticus isolated from patients with a variety of eye infections (n=11) and from healthy conjunctiva (n=7). Minimum inhibitory concentrations were determined for 14 antimicrobials according to BSAC guidelines. PCR was used to identify the presence of mecA, mecC, SCCmec type and ARGs. Sequencing was used to determine mutations in gyrA, gyrB, topoisomerase IVA and IVB genes. Genetic relatedness was determined by PFGE. Of the 18 isolates, 17 showed resistance to at least one antibiotic, but none showed resistance to vancomycin or rifampicin. Ten isolates were oxacillin-resistant and carried the mecA gene, eight of which belonged to SCCmec type V. The presence of non-mec SCC elements in two meticillin-susceptible isolates and untypeable SCC elements in meticillin-resistant isolates suggests the involvement of S. haemolyticus in the diversification of SCC elements. Sequence analysis revealed point mutations in gyrA (Ser-84→Leu) and topoisomerase IVA genes (Ser-80→Leu) in 13 isolates, and additional variation in the QRDR (Asp-84→Asn) of two isolates, showing good correlation between mutations in gyrA and topoisomerase IV genes and the level of resistance to fluoroquinolones. PFGE analysis showed distinct pulsotypes forming two major clusters, indicating the existence of diversity among isolates, irrespective of the source of isolation. This study suggests that S. haemolyticus isolates from infected eyes and healthy conjunctivae invariably carried ARGs and SCCmec elements and showed diversity in their genomic content, irrespective of the source of isolation. Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Implantation of Corynebacterium pseudodiphtheriticum for elimination of Staphylococcus aureus from the nasal cavity in volunteers

NASA Astrophysics Data System (ADS)

Viacheslav, Ilyin; Kiryukhina, Nataliya

Nasal carriage of Staphylococcus aureus is a well-documented risk factor of infection and inflammation of the skin, soft tissues and bacteremia. It is also known that most often etiology of these disorders is associated with autoinfection. The present-day methods of opportunistic pathogens eradication from the nasal cavity are based principally on the use of antiseptic and antibacterial agents. For instance, a local antibiotic mupirocin in the form of nasal ointment is considered to be the gold standard for the treatment of S. aureus carriage. The literature describes investigations showing how mupirocin can strengthen antibiotic resistance in S. aureus strains, including those with methicillin resistance (MRSA). It is also common knowledge that recolonization of the nasal mucous membrane takes place within several months after mupirocin treatment. This circumstance dictates the necessity to look for alternative ways of preventing the S. aureus carriage and methods of elimination. One of the methods of nasal S. aureus elimination is implantation of nonpathogenic microorganisms which will extrude opportunistic pathogens without impinging the symbiotic microbiota. Effectiveness of saline suspension of Corynebacterium pseudodiphtheriticum containing spray was assessed in a several chamber experiments with simulation of some spaceflight factors (dry immersion, isolation). Various schemes of application of preparations were applied. In all cases of corynebacteria application the strong inhibiting effect against S. aureus was detected. This fact opens a prospect of using nonpathogenic corynebacteria as a nasal probiotic. Administration of the nasal corynebacteria spray possibly prevented cross-infection by MRSA and appearance of staphylococcal infection. Further pre-clinical and clinical study of this bacterial therapy method is under development.

Changing characteristics of livestock-associated meticillin-resistant Staphylococcus aureus isolated from humans - emergence of a subclade transmitted without livestock exposure, the Netherlands, 2003 to 2014.

PubMed

Bosch, Thijs; van Luit, Martijn; Pluister, Gerlinde N; Frentz, Dineke; Haenen, Anja; Landman, Fabian; Witteveen, Sandra; van Marm-Wattimena, Naomi; van der Heide, Han G; Schouls, Leo M

2016-05-26

Since 2007, livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) has become the predominant MRSA clade isolated from humans in the Netherlands. To assess possible temporal changes, we molecularly characterised over 9,000 LA-MRSA isolates submitted from 2003 to 2014 to the Dutch MRSA surveillance. After an initial rapid increase with a peak in 2009 (n = 1,368), the total number of submitted LA-MRSA isolates has been slowly decreasing to 968 in 2014 and over 80% of LA-MRSA belonged to one of three predominant MLVA/spa-types. Next generation sequencing (n=118) showed that MT569/t034 isolates were genetically more diverse than MT398/t011 and MT572/t108. Concurrent with the decrease in LA-MRSA, fewer people reported having contact with livestock and this was most prominent for people carrying MT569/t034 LA-MRSA. The proportion of LA-MRSA isolated from infection-related materials increased from 6% in 2009, to 13% in 2014 and most of these isolates originated from patients older than 50 years of age. Remarkably, 83% of these patients reported not having contact with livestock. The results reveal an ongoing change in the genotypic and epidemiological characteristics of Dutch LA-MRSA isolated from humans with the emergence of a LA-MRSA subclade independent of livestock exposure, suggesting LA-MRSA starts to resemble non-LA-MRSA in terms of transmissibility and pathogenicity.

Methicillin-susceptible, Doxycycline-resistant Staphylococcus aureus, Côte d’Ivoire

PubMed Central

Haus-Cheymol, Rachel; Dubrous, Philippe; Verret, Catherine; Spiegel, André; Bonnet, Richard; Bes, Michèle; Laurichesse, Henri; Beytout, Jean; Etienne, Jerome; Migliani, René; Koeck, Jean Louis

2007-01-01

We report 2 outbreaks of Panton-Valentine leukocidin–positive, doxycycline-resistant, methicillin-susceptible Staphylococcus aureus infections in French soldiers operating in Côte d’Ivoire. In a transssectional survey, nasal carriage of this strain was found in 2.9% of 273 soldiers about to be sent to Côte d’Ivoire and was associated with prior malaria prophylaxis with doxycycline. PMID:17552109

High Frequency and Diversity of Antimicrobial Activities Produced by Nasal Staphylococcus Strains against Bacterial Competitors

PubMed Central

Janek, Daniela; Zipperer, Alexander; Kulik, Andreas; Krismer, Bernhard; Peschel, Andreas

2016-01-01

The human nasal microbiota is highly variable and dynamic often enclosing major pathogens such as Staphylococcus aureus. The potential roles of bacteriocins or other mechanisms allowing certain bacterial clones to prevail in this nutrient-poor habitat have hardly been studied. Of 89 nasal Staphylococcus isolates, unexpectedly, the vast majority (84%) was found to produce antimicrobial substances in particular under habitat-specific stress conditions, such as iron limitation or exposure to hydrogen peroxide. Activity spectra were generally narrow but highly variable with activities against certain nasal members of the Actinobacteria, Proteobacteria, Firmicutes, or several groups of bacteria. Staphylococcus species and many other Firmicutes were insusceptible to most of the compounds. A representative bacteriocin was identified as a nukacin-related peptide whose inactivation reduced the capacity of the producer Staphylococcus epidermidis IVK45 to limit growth of other nasal bacteria. Of note, the bacteriocin genes were found on mobile genetic elements exhibiting signs of extensive horizontal gene transfer and rearrangements. Thus, continuously evolving bacteriocins appear to govern bacterial competition in the human nose and specific bacteriocins may become important agents for eradication of notorious opportunistic pathogens from human microbiota. PMID:27490492

Epidemiology and genotypic characteristics of Methicillin-Resistant Staphylococcus aureus strains of porcine origin

USDA-ARS?s Scientific Manuscript database

The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated (LA)-MRSA in pigs and pork. Genotypic relatedness of isolates on-farm, at slaughter and retail was assessed. Paired nasal and peri-anal swab samples we...

Detection of methicillin resistant Staphylococcus aureus (MRSA) from recreational beach using the mecA gene

NASA Astrophysics Data System (ADS)

Zulkifli, Aisya; Ahmad, Asmat

2015-09-01

Water samples were collected in triplicates from three different locations choosen from the recreational beach of Teluk Kemang, Port Dickson as sampling station including main area of recreation activity for the public. Bacteria were isolated from the water and cultured. Out of 286 presumptive Staphylococcus aureus enumerated by using culture method, only 4 (1.4 %) confirmed as Meticillin Resistant S. aureus (MRSA) based on PCR detection of mecA gene. Interestingly, all of MRSA detections were found at the main area of recreational activity. Our results suggested that public beaches may be reservoir for transmission of MRSA to beach visitors and PCR using the mecA gene is the fastest way to detect this pathogenic bacteria.

Dynamic of nasal colonization by methicillin-resistant Staphylococcus aureus ST398 and ST1 after mupirocin treatment in a family in close contact with pigs.

PubMed

Lozano, Carmen; Aspiroz, Carmen; Lasarte, Juan J; Gómez-Sanz, Elena; Zarazaga, Myriam; Torres, Carmen

2011-01-01

Nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA) was evaluated after a mupirocin treatment in a family previously colonized by MRSA sequence type ST398 and ST1, who lived close to a pig farm. Eight nasal samples were swabbed from each of the four family members on different moments after mupirocin treatment. The efficacy of treatment was low in those family members who worked in the farm, and higher in the remaining two family members with sporadic contact with pigs. In addition, nasal and skin swabs from randomly selected pigs of the farm were taken. MRSA were detected in 33% of pigs tested. All MRSA isolates obtained were characterized by Staphylococcal-Cassette-Chromosome mec (SCCmec) determination, Multilocus-Sequence-Typing (MLST), spa- and agr-typing, Pulsed-field-gel-electrophoresis (PFGE), antimicrobial susceptibility, detection of antimicrobial resistance genes, and toxin gene profiling. Spa-types t011, t1255 and t1197 were detected in humans and animals, with indistinguishable PFGE patterns, suggesting animal to human MRSA transmission. Each spa-type was ascribed to a specific pulsotype. Spa-types t127 and t108 were only detected in MRSA isolates obtained from humans, and t012 only in those from animals. MRSA ST1-t127 isolates and some ST398-t011 and ST398-t1197 isolates presented a multiantimicrobial-resistance phenotype. None of them harbored lukF/lukS, tst, eta and etb virulence genes. This study showed that the efficacy of nasal MRSA decolonization in healthy people with very close contact with pigs is especially low. Copyright © 2010 Elsevier Ltd. All rights reserved.

Draft Genome Sequence of a Canine Isolate of Methicillin-Resistant Staphylococcus haemolyticus

PubMed Central

Wigmore, Sarah M.; Wareham, David W.

2017-01-01

ABSTRACT Staphylococcus haemolyticus strain SW007 was isolated from a nasal swab taken from a healthy dog. The isolate is resistant to methicillin, mupirocin, macrolides, and sulfonamides. The SW007 draft genome is 2,325,410 bp and contains 2,277 coding sequences, including 60 tRNAs and nine complete rRNA-coding regions. PMID:28385855

Results of a multicentre randomised controlled trial of statistical process control charts and structured diagnostic tools to reduce ward-acquired meticillin-resistant Staphylococcus aureus: the CHART Project.

PubMed

Curran, E; Harper, P; Loveday, H; Gilmour, H; Jones, S; Benneyan, J; Hood, J; Pratt, R

2008-10-01

Statistical process control (SPC) charts have previously been advocated for infection control quality improvement. To determine their effectiveness, a multicentre randomised controlled trial was undertaken to explore whether monthly SPC feedback from infection control nurses (ICNs) to healthcare workers of ward-acquired meticillin-resistant Staphylococcus aureus (WA-MRSA) colonisation or infection rates would produce any reductions in incidence. Seventy-five wards in 24 hospitals in the UK were randomised into three arms: (1) wards receiving SPC chart feedback; (2) wards receiving SPC chart feedback in conjunction with structured diagnostic tools; and (3) control wards receiving neither type of feedback. Twenty-five months of pre-intervention WA-MRSA data were compared with 24 months of post-intervention data. Statistically significant and sustained decreases in WA-MRSA rates were identified in all three arms (P<0.001; P=0.015; P<0.001). The mean percentage reduction was 32.3% for wards receiving SPC feedback, 19.6% for wards receiving SPC and diagnostic feedback, and 23.1% for control wards, but with no significant difference between the control and intervention arms (P=0.23). There were significantly more post-intervention 'out-of-control' episodes (P=0.021) in the control arm (averages of 0.60, 0.28, and 0.28 for Control, SPC and SPC+Tools wards, respectively). Participants identified SPC charts as an effective communication tool and valuable for disseminating WA-MRSA data.

Adherence capacity of methicillin resistant Staphylococcus aureus sequence type (ST) 5 isolates from health care and agricultural sources

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is part of the nasal microbiome of many humans and has become significant public health burden due to infections with antibiotic resistant versions, including methicillin resistant S. aureus (MRSA). A subset of these isolates are found in livestock species and acquired by human...

[Clinical analysis of nasal resistance and pulmonary function testing in patients with chronic nasal-sinusitis and nasal polyps].

PubMed

Liao, Hua; Shen, Ying; Wang, Pengjun

2015-05-01

To study the pulmonary function and nasal resistance characteristics of patients with chronic nose-sinusitis and nasal polyps (CRSwNP), to explore the evaluation role of nasal resistance in nasal ventilation function and the effect of endoscopic sinus surgery on pulmonary function in patients with CRSwNP. Fifty CRSwNP patients that met the study criteria were selected . The patients were performed endoscopic surgeries according to Messerklinger surgical procedures under general anesthesia. Extent of surgery was based on preoperative CT showing the range of the lesion of disease and endoscopic findings. Perioperative treatments contained intranasal corticosteroids, cephalosporin or penicillin antibiotics, nasal irrigation and other treatments. Main outcome measures included visual analog scale (VAS), endoscopic Lind-Kennedy scores, nasal resistence, pulmonary function in patientsone week before and after surgery, three months and six months after surgery. Pulmonary function includes forced expiratory volume in one second (FEV1), forced vital capacity FEV1/FVC and peak expiratory flow (PEF). The study found that there were significantly positive correlations among VAS score, Lund-Kennedy score and nasal resistance (P < 0.05) in CRSwNP patients, but there is a significantly negative correlation between VAS score, Lund-Kennedy score, nasal resistance and pulmonary function indexes of FEV1, FVC and PEF (P < 0.05). The VAS score, Lund-Kennedy score and nasal resistance values of CRSwNP patients were decreased significantly after comprehensive treatments with nasal endoscopic operation as the major one, the difference was statistically different (P < 0.05). And the pulmonary function indexs (FEV1, FVC, PEF) were significantly increased after surgery in CRSwNP patients. The nasal resistance can objectively and reliably reflect the degree of nasal congestion and the recovery of nasal function in CRSwNP patients after endoscopic sinus surgery. The detection method of nasal

Epidemiology and molecular characterization of methicillin-resistant Staphylococcus aureus nasal carriage isolates from bovines

PubMed Central

2014-01-01

Background Staphylococcus aureus is a common bacterium usually found on skin and mucous membranes of warm blooded animals. Resistance in S. aureus has been increasingly reported though depending on the clonal lineage. Indeed, while hospital acquired (HA)-methicillin resistant S. aureus (MRSA) are typically multi-resistant, community associated (CA)-MRSA are by large more susceptible to many antibiotics. Although S. aureus isolated from animals are often susceptible to most antibiotics, multi-resistant livestock associated (LA)-MRSA have been recovered from bovine mastitis. In this study, we investigated the prevalence and types of MRSA present in the nose of healthy bovines of different age groups and rearing practices. Since no validated methods for MRSA isolation from nasal swabs were available, we compared two isolation methods. Molecular characterization was performed by means of spa-typing, MLST, SCCmec typing and microarray analysis for the detection of antimicrobial resistance and virulence genes. Results MRSA between herd prevalence in bovines was estimated at 19.8%. There was a marked difference between rearing practices with 9.9%, 10.2% and 46.1% of the dairy, beef and veal calve farms respectively being MRSA positive. No significant difference was observed between both isolation methods tested. Most isolates were ST398 spa type t011 or closely related spa types. Few ST239 spa type t037 and t388 and ST8 spa type t121 were also found. SCCmec types carried by these strains were mainly type IV(2B), IV(2B&5) and type V. Type III and non-typeable SCCmec were recovered to a lesser extent. All isolates were multi-resistant to at least two antimicrobials in addition to the expected cefoxitin and penicillin resistance, with an average of resistance to 9.5 different antimicrobials. Isolates selected for microarray analysis carried a broad range of antimicrobial resistance and virulence genes. Conclusion MRSA were mainly present in veal farms, compared to the lower

Draft Genome Sequence of a Canine Isolate of Methicillin-Resistant Staphylococcus haemolyticus.

PubMed

Bean, David C; Wigmore, Sarah M; Wareham, David W

2017-04-06

Staphylococcus haemolyticus strain SW007 was isolated from a nasal swab taken from a healthy dog. The isolate is resistant to methicillin, mupirocin, macrolides, and sulfonamides. The SW007 draft genome is 2,325,410 bp and contains 2,277 coding sequences, including 60 tRNAs and nine complete rRNA-coding regions. Copyright © 2017 Bean et al.

Assessment of Nasal Carriage of Staphylococcus Aureus and Axillar Flora in Patients With Acromegaly.

PubMed

Gen, Ramazan; Horasan, Elif Şahin; Çinkir, Ümit; Sezer, Kerem; Akbay, Esen

2017-05-01

Recent study showed that patients with acromegaly have typical skin findings including increased sebum secretion, decreased transepidermal water loss, more alkaline, and colder skin surface correlated with serum growth hormone and insulin-like growth factor 1 levels. Different anatomic localizations and texture of the skin differ in bacterial concentrations.Nasal carriage of Staphylococcus aureus and axillar flora in patients with acromegaly was compared with normal population with regard to duration of acromegaly as well as the growth hormone and insulin-like growth factor 1 levels. This patient-control prospective study was conducted in university hospitals in Mersin, Turkey. The study consisted of 30 active acromegalic patients and 60 healthy adults who had no previously diagnosed chronic illness as a control group. A total of 90 volunteers were enrolled in this study; nasal and axillar cultures were obtained. Axillar and nasal specimens from anterior nares of the individuals were taken using sterile swabs. Nasal colonization of Staphylococcus aureus was 13.3% in acromegalic patients, but 43.4% in control group. This difference was statistically significant (P = 0.004). Patients and control group compared according to axillar cultures, the authors determined proteus colonization 16.7% in patients with acromegaly but no proteus colonization in control group. This result was statistically significant (P = 0.001). Proteus colonization was negatively correlated only with disease duration in acromegalic patients (P = 0.017). The authors demonstrated that compared with healthy subjects, acromegalic patients had low percentage of nasal carriage of Staphylococcus aureus and more gram-negative basili in the axillar flora. These nasal and axillar flora changes should be considered for prophylactic antibiotics use before surgery and ampiric antibiotics use after surgery.

Infection control strategies for preventing the transmission of meticillin-resistant Staphylococcus aureus (MRSA) in nursing homes for older people.

PubMed

Hughes, Carmel; Smith, Michael; Tunney, Michael; Bradley, Marie C

2011-12-07

Nursing homes for older people provide an environment likely to promote the acquisition and spread of meticillin-resistant Staphylococcus aureus (MRSA), putting residents at increased risk of colonisation and infection. It is recognised that infection prevention and control strategies are important in preventing and controlling MRSA transmission. To determine the effects of infection prevention and control strategies for preventing the transmission of MRSA in nursing homes for older people. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2011, Issue 2), the Cochrane Wounds Group Specialised Register (searched May 27th, 2011). We also searched Ovid MEDLINE (from 1950 to April Week 2 2011), OVID MEDLINE (In-process and Other Non-Indexed Citations, April 26th 2011) Ovid EMBASE (1980 to 2011 Week 16), EBSCO CINAHL (1982 to April 21st 2011), DARE (1992 to 2011, week 16), Web of Science (1981 to May 2011), and the Health Technology Assessment (HTA) website (1988 to May 2011). Research in progress was sought through Current Clinical Trials (www.controlled-trials.com), Medical Research Council Research portfolio, and HSRPRoj (current USA projects). All randomised and controlled clinical trials, controlled before and after studies and interrupted time series studies of infection prevention and control interventions in nursing homes for older people were eligible for inclusion. Two review authors independently reviewed the results of the searches. Another review author appraised identified papers and undertook data extraction which was checked by a second review author. For this second update only one study was identified, therefore it was not possible to undertake a meta-analysis. A cluster randomised controlled trial in 32 nursing homes evaluated the effect of an infection control education and training programme on MRSA prevalence. The primary outcome was MRSA prevalence in residents and staff, and a change in infection

Bacteriophage-derived CHAP domain protein, P128, kills Staphylococcus cells by cleaving interpeptide cross-bridge of peptidoglycan.

PubMed

Sundarrajan, Sudarson; Raghupatil, Junjappa; Vipra, Aradhana; Narasimhaswamy, Nagalakshmi; Saravanan, Sanjeev; Appaiah, Chemira; Poonacha, Nethravathi; Desai, Srividya; Nair, Sandhya; Bhatt, Rajagopala Narayana; Roy, Panchali; Chikkamadaiah, Ravisha; Durgaiah, Murali; Sriram, Bharathi; Padmanabhan, Sriram; Sharma, Umender

2014-10-01

P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains. © 2014 The Authors.

Molecular epidemiology of Staphylococcus aureus nasal colonization among patients and their parents /guardian in an Iranian referral hospital.

PubMed

Pourakbari, Babak; Khodabandeh, Mahmoud; Mahmoudi, Shima; Sabouni, Farah; Aziz-Ahari, Alireza; Bahador, Abbas; Keshavarz Valian, Sepideh; Hosseinpour Sadeghi, Reihaneh; Mamishi, Setareh

2017-06-01

Carriage of Staphylococcus aureus in the nose appears to play a key role in the epidemiology and pathogenesis of infection. It is important to investigate the genetic relatedness of S. aureus and MRSA clones in different geographic regions. The aim of this study was to assess the nasal carriage rate of S. aureus, including MRSA strains in both hospitalized children and general adult population (parents/guardian). In addition, antibiotic susceptibility pattern and molecular diversity of S. aureus in both population was evaluated in an Iranian referral pediatrics Hospital. All samples were obtained through nasal screening of patients and general adult population at admission and discharge day. The prevalence, resistance, and molecular diversity of all S. aureus isolates were examined. In the current study, nasal carriage of S. aureus and Staphylococcus non aureus was identified in 384 (26%) and 1004 (68%) of the study population. The prevalence of MRSA nasal carriage in children and adults was 6.6% (29 out of 438) and 2.8% (29 out of 1046), respectively. Among S. aureus strains isolated obtained from patients and general adult population at admission day, high sensitivity to most of the antibiotics such as vancomycin (100%), rifampin (95%), linezolid (94%), quinupristin/dalfopristin (94%), minocycline (94%), chloramphenicol (89%), gentamycin (87%), amikacin (87%), clindamycin (86%) and moxifloxacin (83%) was seen. The most resistance antibiotics were penicillin (96-98%) and methicillin (44-47%). The susceptibility patterns of nasal S. aureus strains isolated at discharge day was not statistically different from S. aureus isolates obtained at admission day. Admission S. aureus isolated strains of 77 patients (64%) were similar to the isolated S. aureus strains of discharge, while S. aureus isolated strains of 43 patients (36%) was not similar to the strain of discharge (had similarity of less than 70%). High prevalence of nasal carriage of S. aureus and

[Nasal septal abscess].

PubMed

Barril, María F; Ferolla, Fausto M; José, Pablo; Echave, Cecilia; Tomezzoli, Silvana; Fiorini, Sandra; López, Eduardo Luis

2008-12-01

A nasal septal abscess (NA) is defined as a collection of pus between the cartilage or bony septum and its normally applied mucoperichondrium or mucoperiostium. It is an uncommon disease which should be suspected in a patient with acute onset of nasal obstruction and recent history of nasal trauma, periodontal infection or an inflammatory process of the rhinosinusal region. We report a case of an 8-year-old boy with bilateral NA caused by community-acquired methicillin-resistant Staphylococcus aureus(MR-CO) in order to emphasize the importance of prompt diagnosis and adequate treatment to prevent the potentially dangerous spread of infection and the development of severe functional and cosmetic sequelae.

The prevalence of carriage of meticillin-resistant staphylococci by veterinary dermatology practice staff and their respective pets.

PubMed

Morris, Daniel O; Boston, Raymond C; O'Shea, Kathleen; Rankin, Shelley C

2010-08-01

It has been shown that people and pets can harbour identical strains of meticillin-resistant (MR) staphylococci when they share an environment. Veterinary dermatology practitioners are a professional group with a high incidence of exposure to animals infected by Staphylococcus spp. The objective of this study was to assess the prevalence of carriage of MR Staphylococcus aureus (MRSA), MR S. pseudintermedius (MRSP) and MR S. schleiferi (MRSS) by veterinary dermatology practice staff and their personal pets. A swab technique and selective media were used to screen 171 veterinary dermatology practice staff and their respective pets (258 dogs and 160 cats). Samples were shipped by over-night carrier. Human subjects completed a 22-question survey of demographic and epidemiologic data relevant to staphylococcal transmission. The 171 human-source samples yielded six MRSA (3.5%), nine MRSP (5.3%) and four MRSS (2.3%) isolates, while 418 animal-source samples yielded eight MRSA (1.9%) 21 MRSP (5%), and two MRSS (0.5%) isolates. Concordant strains (genetically identical by pulsed-field gel electrophoresis) were isolated from human subjects and their respective pets in four of 171 (2.9%) households: MRSA from one person/two pets and MRSP from three people/three pets. In seven additional households (4.1%), concordant strains were isolated from only the pets: MRSA in two households and MRSP in five households. There were no demographic or epidemiologic factors statistically associated with either human or animal carriage of MR staphylococci, or with concordant carriage by person-pet or pet-pet pairs. Lack of statistical associations may reflect an underpowered study. © 2010 The Authors. Journal compilation © 2010 ESVD and ACVD.

Prevalence of Staphylococcus spp. nasal colonization among doctors of podiatric medicine and associated risk factors in Spain.

PubMed

de Benito, Sheila; Alou, Luis; Becerro-de-Bengoa-Vallejo, Ricardo; Losa-Iglesias, Marta Elena; Gómez-Lus, María Luisa; Collado, Luis; Sevillano, David

2018-01-01

This study aimed to estimate the prevalence of methicillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) nasopharyngeal carriage among Doctors of Podiatric Medicine (Podiatrists) and to determine the potential risk factors. A cross-sectional study was carried out in 2016-2017 among 239 podiatrists in Spain. The presence of MSSA, MRSA, and MRSE was determined by microbiological analysis of nasal exudate and antimicrobial susceptibility was determined. Each podiatrist completed a questionnaire. The questionnaire comprised various parameters such as sex, age, podiatry experience duration, underlying diseases, prior antibiotic treatment, hospitalization during the last year, and use of a protective mask, an aspiration system, or gloves. The prevalence of MSSA, MRSA, and MRSE was 23.0%, 1.3%, and 23.8%, respectively. The MSSA prevalence was higher among podiatrists who did not use an aspiration system (32.3%) compared to those who did (19.3%; p  = 0.0305), and among podiatrists with respiratory diseases (36.8%) compared to those without (20.8%; p  = 0.0272). The MRSE prevalence was higher among men (33.7%) compared to women (8.6%; p  = 0.0089), podiatrists aged ≥50 (38.5%) compared to ≤35 (17.8%; p  = 0.0101), and podiatrists with ≥15 (39.3%) compared to ≤5 years of podiatry experience (12.5%; p  = 0.0015). Among the S. aureus strains, 84.5% were resistant to penicillin, 22.4% to erythromycin, 20.7% to clindamycin, and 12.7% to mupirocin. The MRSE strains were resistant to penicillin (93.0%), erythromycin (78.9%), and mupirocin (73.7%). The prevalence of S. aureus and S. epidermidis nasal carriage is low among Spanish podiatrists compared to other health professionals.

Gloves, gowns and masks for reducing the transmission of meticillin-resistant Staphylococcus aureus (MRSA) in the hospital setting.

PubMed

López-Alcalde, Jesús; Mateos-Mazón, Marta; Guevara, Marcela; Conterno, Lucieni O; Solà, Ivan; Cabir Nunes, Sheila; Bonfill Cosp, Xavier

2015-07-16

Meticillin-resistant Staphylococcus aureus (MRSA; also known as methicillin-resistant S aureus) is a common hospital-acquired pathogen that increases morbidity, mortality, and healthcare costs. Its control continues to be an unresolved issue in many hospitals worldwide. The evidence base for the effects of the use of gloves, gowns or masks as control measures for MRSA is unclear. To assess the effectiveness of wearing gloves, a gown or a mask when contact is anticipated with a hospitalised patient colonised or infected with MRSA, or with the patient's immediate environment. We searched the Specialised Registers of three Cochrane Groups (Wounds Group on 5 June 2015; Effective Practice and Organisation of Care (EPOC) Group on 9 July 2013; and Infectious Diseases Group on 5 January 2009); CENTRAL (The Cochrane Library 2015, Issue 6); DARE, HTA, NHS EED, and the Methodology Register (The Cochrane Library 2015, Issue 6); MEDLINE and MEDLINE In-Process & Other Non-Indexed Citations (1946 to June week 1 2015); EMBASE (1974 to 4 June 2015); Web of Science (WOS) Core Collection (from inception to 7 June 2015); CINAHL (1982 to 5 June 2015); British Nursing Index (1985 to 6 July 2010); and ProQuest Dissertations & Theses Database (1639 to 11 June 2015). We also searched three trials registers (on 6 June 2015), references list of articles, and conference proceedings. We finally contacted relevant individuals for additional studies. Studies assessing the effects on MRSA transmission of the use of gloves, gowns or masks by any person in the hospital setting when contact is anticipated with a hospitalised patient colonised or infected with MRSA, or with the patient's immediate environment. We did not assess adverse effects or economic issues associated with these interventions.We considered any comparator to be eligible. With regard to study design, only randomised controlled trials (clustered or not) and the following non-randomised experimental studies were eligible: quasi

Incidence and characterisation of methicillin-resistant Staphylococcus aureus (MRSA) from nasal colonisation in participants attending a cattle veterinary conference in the UK.

PubMed

Paterson, Gavin K; Harrison, Ewan M; Craven, Emily F; Petersen, Andreas; Larsen, Anders Rhod; Ellington, Matthew J; Török, M Estée; Peacock, Sharon J; Parkhill, Julian; Zadoks, Ruth N; Holmes, Mark A

2013-01-01

We sought to determine the prevalence of nasal colonisation with methicillin-resistant Staphylococcus aureus among cattle veterinarians in the UK. There was particular interest in examining the frequency of colonisation with MRSA harbouring mecC, as strains with this mecA homologue were originally identified in bovine milk and may represent a zoonotic risk to those in contact with dairy livestock. Three hundred and seven delegates at the British Cattle Veterinarian Association (BCVA) Congress 2011 in Southport, UK were screening for nasal colonisation with MRSA. Isolates were characterised by whole genome sequencing and antimicrobial susceptibility testing. Eight out of three hundred and seven delegates (2.6%) were positive for nasal colonisation with MRSA. All strains were positive for mecA and none possessed mecC. The time since a delegate's last visit to a farm was significantly shorter in the MRSA-positive group than in MRSA-negative counterparts. BCVA delegates have an increased risk of MRSA colonisation compared to the general population but their frequency of colonisation is lower than that reported from other types of veterinarian conference, and from that seen in human healthcare workers. The results indicate that recent visitation to a farm is a risk factor for MRSA colonisation and that mecC-MRSA are rare among BCVA delegates (<1% based on sample size). Contact with livestock, including dairy cattle, may still be a risk factor for human colonisation with mecC-MRSA but occurs at a rate below the lower limit of detection available in this study.

Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from an At-Risk Community Population▿

PubMed Central

Farley, Jason E.; Stamper, Paul D.; Ross, Tracy; Cai, Mian; Speser, Sharon; Carroll, Karen C.

2008-01-01

We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus. PMID:18057129

Cost-effectiveness of supplementing a broth-enriched culture test with the Xpert meticillin-resistant Staphylococcus aureus (MRSA) assay for screening inpatients at high risk of MRSA.

PubMed

Li, J; Ulvin, K; Biboh, H; Kristiansen, I S

2012-12-01

Meticillin-resistant Staphylococcus aureus (MRSA) represents a considerable challenge for health care in terms of complications and costs. Whilst bacteriological culture remains the most common method for detecting MRSA, the polymerase-chain-reaction-based Xpert MRSA assay was introduced to Ullevål Oslo University Hospital, Norway in 2009. To estimate the cost-effectiveness of supplementing a broth-enriched culture test with the Xpert MRSA assay in comparison with using the culture test alone as part of an active surveillance strategy. A decision-tree model was developed to compare the current strategy (broth-enriched culture test) with two new strategies using the Xpert MRSA assay (daytime and 24 h). Costs and outcomes (length of pre-emptive isolation, number of unavailable room-hours, quality of life) were measured. The current strategy was more expensive (NOK16,984 per patient) than the daytime Xpert strategy and 24 h Xpert strategy (NOK7360 and NOK3690 per patient, respectively). The new strategies reduced the length of pre-emptive isolation per patient (by 43.9 h and 57.5 h for the daytime Xpert strategy and 24 h Xpert strategy, respectively), and also the number of unavailable room-hours per case (by 57.1 h and 77.7 h, respectively). The improvement in patients' quality-adjusted life years (QALYs) was nominal (2.4*10(-4) and 3.0*10(-4) QALYs per patient for the daytime Xpert strategy and 24 h Xpert strategy, respectively). The sensitivity analyses indicated that these results were robust to reasonable changes in the model parameters. The 24 h Xpert strategy appears to be the best strategy for active surveillance as it reduces costs and unfavourable outcomes compared with the other strategies, while improving favourable outcomes under reasonable assumptions. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Perceiving nasal patency through mucosal cooling rather than air temperature or nasal resistance.

PubMed

Zhao, Kai; Blacker, Kara; Luo, Yuehao; Bryant, Bruce; Jiang, Jianbo

2011-01-01

Adequate perception of nasal airflow (i.e., nasal patency) is an important consideration for patients with nasal sinus diseases. The perception of a lack of nasal patency becomes the primary symptom that drives these patients to seek medical treatment. However, clinical assessment of nasal patency remains a challenge because we lack objective measurements that correlate well with what patients perceive. The current study examined factors that may influence perceived patency, including air temperature, humidity, mucosal cooling, nasal resistance, and trigeminal sensitivity. Forty-four healthy subjects rated nasal patency while sampling air from three facial exposure boxes that were ventilated with untreated room air, cold air, and dry air, respectively. In all conditions, air temperature and relative humidity inside each box were recorded with sensors connected to a computer. Nasal resistance and minimum airway cross-sectional area (MCA) were measured using rhinomanometry and acoustic rhinometry, respectively. General trigeminal sensitivity was assessed through lateralization thresholds to butanol. No significant correlation was found between perceived patency and nasal resistance or MCA. In contrast, air temperature, humidity, and butanol threshold combined significantly contributed to the ratings of patency, with mucosal cooling (heat loss) being the most heavily weighted predictor. Air humidity significantly influences perceived patency, suggesting that mucosal cooling rather than air temperature alone provides the trigeminal sensation that results in perception of patency. The dynamic cooling between the airstream and the mucosal wall may be quantified experimentally or computationally and could potentially lead to a new clinical evaluation tool.

Nasal carriage of Staphylococcus schleiferi from healthy dogs and dogs with otitis, pyoderma or both.

PubMed

May, Elizabeth R; Kinyon, Joann M; Noxon, James O

2012-12-07

In veterinary medicine, Staphylococcus schleiferi was previously assumed to be an inhabitant of carnivore skin, however, more recently, it has been repeatedly documented in the literature as both an inhabitant and as a pathogen. In order to determine the frequency of nasal carriage, and the methicillin susceptibility pattern of S. schleiferi from healthy dogs as well as dogs with otitis and/or pyoderma, a prospective study including 24 dogs with healthy ears and skin, 27 dogs with healthy ears and pyoderma, 15 dogs with otitis without pyoderma and 20 dogs with both otitis and pyoderma was performed. Specimens were obtained and cultured and isolates were identified as S. schleiferi based on growth and biochemical characteristics. S. schleiferi was isolated from the nares of 1 healthy dog, 3 dogs with recurrent pyoderma, 2 dogs with recurrent otitis, and 1 dog with both recurrent otitis and pyoderma. One of the S. schleiferi isolates was methicillin resistant. Nasal carriage of S. schleiferi does occur in healthy dogs as well as dogs with otitis and pyoderma. Methicillin resistant and sensitive S. schleiferi can be found in the nares of dogs with diseased ears and skin. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecular typing of antibiotic-resistant Staphylococcus aureus in Nigeria.

PubMed

O'Malley, S M; Emele, F E; Nwaokorie, F O; Idika, N; Umeizudike, A K; Emeka-Nwabunnia, I; Hanson, B M; Nair, R; Wardyn, S E; Smith, T C

2015-01-01

Antibiotic-resistant Staphylococcus aureus including methicillin-resistant strains (MRSA) are a major concern in densely populated urban areas. Initial studies of S. aureus in Nigeria indicated existence of antibiotic-resistant S. aureus strains in clinical and community settings. 73 biological samples (40 throat, 23 nasal, 10 wound) were collected from patients and healthcare workers in three populations in Nigeria: Lagos University Teaching Hospital, Nigerian Institute of Medical Research, and Owerri General Hospital. S. aureus was isolated from 38 of 73 samples (52%). Of the 38 S. aureus samples, 9 (24%) carried the Panton-Valentine leukocidin gene (PVL) while 16 (42%) possessed methicillin resistance genes (mecA). Antibiotic susceptibility profiles indicated resistance to several broad-spectrum antibiotics. Antibiotic-resistant S. aureus isolates were recovered from clinical and community settings in Nigeria. Insight about S. aureus in Nigeria may be used to improve antibiotic prescription methods and minimize the spread of antibiotic-resistant organisms in highly populated urban communities similar to Lagos, Nigeria. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Nasal Carriage of Staphylococcus aureus among Children in the Ashanti Region of Ghana.

PubMed

Eibach, Daniel; Nagel, Michael; Hogan, Benedikt; Azuure, Clinton; Krumkamp, Ralf; Dekker, Denise; Gajdiss, Mike; Brunke, Melanie; Sarpong, Nimako; Owusu-Dabo, Ellis; May, Jürgen

2017-01-01

Nasal carriage with Staphylococcus aureus is a common risk factor for invasive infections, indicating the necessity to monitor prevalent strains, particularly in the vulnerable paediatric population. This surveillance study aims to identify carriage rates, subtypes, antimicrobial susceptibilities and virulence markers of nasal S. aureus isolates collected from children living in the Ashanti region of Ghana. Nasal swabs were obtained from children < 15 years of age on admission to the Agogo Presbyterian Hospital between April 2014 and January 2015. S. aureus isolates were characterized by their antimicrobial susceptibility, the presence of genes encoding for Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin-1 (TSST-1) and further differentiated by spa-typing and multi-locus-sequence-typing. Out of 544 children 120 (22.1%) were colonized with S. aureus, with highest carriage rates during the rainy seasons (27.2%; p = 0.007), in females aged 6-8 years (43.7%) and males aged 8-10 years (35.2%). The 123 isolates belonged to 35 different spa-types and 19 sequence types (ST) with the three most prevalent spa-types being t355 (n = 25), t84 (n = 18), t939 (n = 13), corresponding to ST152, ST15 and ST45. Two (2%) isolates were methicillin-resistant S. aureus (MRSA), classified as t1096 (ST152) and t4454 (ST45), and 16 (13%) were resistant to three or more different antimicrobial classes. PVL and TSST-1 were detected in 71 (58%) and 17 (14%) isolates respectively. S. aureus carriage among Ghanaian children seems to depend on age, sex and seasonality. While MRSA rates are low, the high prevalence of PVL is of serious concern as these strains might serve not only as a source for severe invasive infections but may also transfer genes, leading to highly virulent MRSA clones.

Perceiving Nasal Patency through Mucosal Cooling Rather than Air Temperature or Nasal Resistance

PubMed Central

Zhao, Kai; Blacker, Kara; Luo, Yuehao; Bryant, Bruce; Jiang, Jianbo

2011-01-01

Adequate perception of nasal airflow (i.e., nasal patency) is an important consideration for patients with nasal sinus diseases. The perception of a lack of nasal patency becomes the primary symptom that drives these patients to seek medical treatment. However, clinical assessment of nasal patency remains a challenge because we lack objective measurements that correlate well with what patients perceive.The current study examined factors that may influence perceived patency, including air temperature, humidity, mucosal cooling, nasal resistance, and trigeminal sensitivity. Forty-four healthy subjects rated nasal patency while sampling air from three facial exposure boxes that were ventilated with untreated room air, cold air, and dry air, respectively. In all conditions, air temperature and relative humidity inside each box were recorded with sensors connected to a computer. Nasal resistance and minimum airway cross-sectional area (MCA) were measured using rhinomanometry and acoustic rhinometry, respectively. General trigeminal sensitivity was assessed through lateralization thresholds to butanol. No significant correlation was found between perceived patency and nasal resistance or MCA. In contrast, air temperature, humidity, and butanol threshold combined significantly contributed to the ratings of patency, with mucosal cooling (heat loss) being the most heavily weighted predictor. Air humidity significantly influences perceived patency, suggesting that mucosal cooling rather than air temperature alone provides the trigeminal sensation that results in perception of patency. The dynamic cooling between the airstream and the mucosal wall may be quantified experimentally or computationally and could potentially lead to a new clinical evaluation tool. PMID:22022361

[Dispersal of Staphylococcus aureus from nasal carriers].

PubMed

Iskandar, Aline; Nguyen, Ngan; Kolmos, Hans Jørn

2009-02-02

Staphylococcus aureus (Sa) is an important cause of hospital-acquired infections, and nasal carriage of Sa is common among health care workers. This study was designed to measure the airborne dispersal of Sa and other bacteria from such carriers and to investigate whether the use of cap, gown, gloves, and mask could reduce this dispersal. A total of 13 nasal Sa carriers were identified among 63 persons screened for Sa nasal carriage. The volunteers were studied for airborne dispersal of Sa in four different situations: quiet breathing, movements of the arms, whispering and loud talking. These activities were performed with and without gown, gloves, mask and cap upon street clothes. The study showed that the highest number of Sa and bacteria in total was dispersed into the air when the volunteers were moving and wearing only their street clothes. The dispersal of Sa into the air was reduced into a minimum by wearing cap, gown and gloves, and no further significant decrease was achieved by wearing a mask. This applied for all volunteers except for one, who had to wear a mask in order to reduce his dispersal of Sa to a minimum. The total dispersal of bacteria was significantly reduced by wearing cap, gown and gloves; however, to reduce this dispersal to a minimum, volunteers also had to wear a mask. Our study supports the rational basis that gown, cap, gloves and mask should be used not only in the operating theatre, but also while e.g. inserting central venous catheters.

Nasal Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Testing Reduces the Duration of MRSA-Targeted Therapy in Patients with Suspected MRSA Pneumonia.

PubMed

Baby, Nidhu; Faust, Andrew C; Smith, Terri; Sheperd, Lyndsay A; Knoll, Laura; Goodman, Edward L

2017-04-01

The objective of this study was to evaluate the impact of pharmacist-ordered methicillin-resistant Staphylococcus aureus (MRSA) PCR testing on the duration of empirical MRSA-targeted antibiotic therapy in patients with suspected pneumonia. This is a retrospective analysis of patients who received vancomycin or linezolid for suspected pneumonia before and after the implementation of a pharmacist-driven protocol for nasal MRSA PCR testing. Patients were included if they were adults of >18 years of age and initiated on vancomycin or linezolid for suspected MRSA pneumonia. The primary endpoint was the duration of vancomycin or linezolid therapy. After screening 368 patients, 57 patients met inclusion criteria (27 pre-PCR and 30 post-PCR). Baseline characteristics were similar between the two groups, with the majority of patients classified as having health care-associated pneumonia (68.4%). The use of the nasal MRSA PCR test reduced the mean duration of MRSA-targeted therapy by 46.6 h (74.0 ± 48.9 h versus 27.4 ± 18.7 h; 95% confidence interval [CI], 27.3 to 65.8 h; P < 0.0001). Fewer patients in the post-PCR group required vancomycin serum levels and dose adjustment (48.1% versus 16.7%; P = 0.02). There were no significant differences between the pre- and post-PCR groups regarding days to clinical improvement (1.78 ± 2.52 versus 2.27 ± 3.34; P = 0.54), length of hospital stay (11.04 ± 9.5 versus 8.2 ± 7.8; P = 0.22), or hospital mortality (14.8% versus 6.7%; P = 0.41). The use of nasal MRSA PCR testing in patients with suspected MRSA pneumonia reduced the duration of empirical MRSA-targeted therapy by approximately 2 days without increasing adverse clinical outcomes. Copyright © 2017 American Society for Microbiology.

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Swiss veterinary health care providers: detection of livestock- and healthcare-associated clones.

PubMed

Wettstein Rosenkranz, K; Rothenanger, E; Brodard, I; Collaud, A; Overesch, G; Bigler, B; Marschall, J; Perreten, V

2014-07-01

We screened a total of 340 veterinarians (including general practitioners, small animal practitioners, large animal practitioners, veterinarians working in different veterinary services or industry), and 29 veterinary assistants for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) at the 2012 Swiss veterinary annual meeting. MRSA isolates (n = 14) were detected in 3.8 % (95 % CI 2.1 - 6.3 %) of the participants whereas MRSP was not detected. Large animal practitioners were carriers of livestock-associated MRSA (LA-MRSA) ST398-t011-V (n = 2), ST398-t011-IV (n = 4), and ST398-t034-V (n = 1). On the other hand, participants working with small animals harbored human healthcare-associated MRSA (HCA-MRSA) which belonged to epidemic lineages ST225-t003-II (n = 2), ST225-t014-II (n = 1), ST5-t002-II (n = 2), ST5-t283-IV (n = 1), and ST88-t186-IV (n = 1). HCA-MRSA harbored virulence factors such as enterotoxins, β-hemolysin converting phage and leukocidins. None of the MRSA isolates carried Panton-Valentine leukocidin (PVL). In addition to the methicillin resistance gene mecA, LA-MRSA ST398 isolates generally contained additional antibiotic resistance genes conferring resistance to tetracycline [tet(M) and tet(K)], trimethoprim [dfrK, dfrG], and the aminoglycosides gentamicin and kanamycin [aac(6')-Ie - aph(2')-Ia]. On the other hand, HCA-MRSA ST5 and ST225 mainly contained genes conferring resistance to the macrolide, lincosamide and streptogramin B antibiotics [erm(A)], to spectinomycin [ant(9)-Ia], amikacin and tobramycin [ant(4')-Ia], and to fluoroquinolones [amino acid substitutions in GrlA (S84L) and GyrA (S80F and S81P)]. MRSA carriage may represent an occupational risk and veterinarians should be aware of possible MRSA colonization and potential for developing infection or for transmitting these strains. Professional exposure to animals should be reported upon hospitalization and before medical

SCC mec typing and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) from pigs of Northeast India.

PubMed

Rajkhowa, S; Sarma, D K; Pegu, S R

2016-12-01

Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1-3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.

Methicillin-Resistant and Methicillin-Sensitive Staphylococcus aureus Screening and Decolonization to Reduce Surgical Site Infection in Elective Total Joint Arthroplasty.

PubMed

Sporer, Scott M; Rogers, Thea; Abella, Linda

2016-09-01

Deep infection after elective total joint arthroplasty remains a devastating complication. Preoperative nasal swab screening for Staphylococcus aureus colonization and subsequent treatment of colonized patients is one proposed method to identify at-risk patients and decrease surgical site infections (SSIs). The purpose of this study was to determine whether a preoperative staphylococcus screening and treatment program would decrease the incidence of SSI in elective joint arthroplasty patients. Since January 2009, a total of 9690 patients having an elective joint arthroplasty were screened before surgery for Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) with nares swabs. All patients with positive nare colonization for MSSA and MRSA were treated with mupirocin and chlorhexidine gluconate showers for 5 days before surgery. MRSA patients received vancomycin preoperatively and were placed in contact isolation. All elective arthroplasty patients used chlorhexidine gluconate antiseptic cloths the evening prior and the day of surgery. Perioperative infection rates were compared from 1 year before implementation to 5 years after implementation of this screening protocol. SSI rates have decreased from 1.11% (prescreening) to 0.34% (nasal screening; P < .05) after initiation of the process. Staphylococcus was identified in 66.7% of the SSI infections before nasal screening and in 33.3% of the SSI after routine screening (P > .05). The addition of MRSA and/or MSSA nares screening along with a perioperative decolonization protocol has resulted in a decreased SSI rate by 69%. Copyright © 2016 Elsevier Inc. All rights reserved.

Nasal carriers are more likely to acquire exogenous Staphylococcus aureus strains than non-carriers.

PubMed

Ghasemzadeh-Moghaddam, H; Neela, V; van Wamel, W; Hamat, R A; Shamsudin, M Nor; Hussin, N Suhaila Che; Aziz, M N; Haspani, M S Mohammad; Johar, A; Thevarajah, S; Vos, M; van Belkum, A

2015-11-01

We performed a prospective observational study in a clinical setting to test the hypothesis that prior colonization by a Staphylococcus aureus strain would protect, by colonization interference or other processes, against de novo colonization and, hence, possible endo-infections by newly acquired S. aureus strains. Three hundred and six patients hospitalized for >7 days were enrolled. For every patient, four nasal swabs (days 1, 3, 5, and 7) were taken, and patients were identified as carriers when a positive nasal culture for S. aureus was obtained on day 1 of hospitalization. For all patients who acquired methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus via colonization and/or infection during hospitalization, strains were collected. We note that our study may suffer from false-negative cultures, local problems with infection control and hospital hygiene, or staphylococcal carriage at alternative anatomical sites. Among all patients, 22% were prior carriers of S. aureus, including 1.9% whom carried MRSA upon admission. The overall nasal staphylococcal carriage rate among dermatology patients was significantly higher than that among neurosurgery patients (n = 25 (55.5%) vs. n = 42 (16.1%), p 0.005). This conclusion held when the carriage definition included individuals who were nasal culture positive on day 1 and day 3 of hospitalization (p 0.0001). All MRSA carriers were dermatology patients. There was significantly less S. aureus acquisition among non-carriers than among carriers during hospitalization (p 0.005). The mean number of days spent in the hospital before experiencing MRSA acquisition in nasal carriers was 5.1, which was significantly lower than the score among non-carriers (22 days, p 0.012). In conclusion, we found that nasal carriage of S. aureus predisposes to rather than protects against staphylococcal acquisition in the nose, thereby refuting our null hypothesis. Copyright © 2015 European Society of Clinical

[Staphylococcus aureus nasal colonization in medical students: importance in nosocomial transmission].

PubMed

López-Aguilera, Sara; Goñi-Yeste, María Del Mar; Barrado, Laura; González-Rodríguez-Salinas, M Carmen; Otero, Joaquín R; Chaves, Fernando

2013-10-01

Staphylococcus aureus is the main pathogen causing nosocomial infections. Health professionals, including medical students, could be a source of transmission. The aims of the study were to determine the rate of nasal carriage of S.aureus susceptible and resistant to methicillin (MRSA) and evaluate the knowledge and adherence that students had about hand hygiene. The study included medical students attached to the Hospital Universitario 12 de Octubre (Madrid, Spain). We collected samples from both nasal vestibules, and the antimicrobial susceptibility was determined on all isolates. Data collection was performed using a self-administered questionnaire that included risk factors for colonization, hygiene habits and knowledge of hand hygiene protocols. Of the 140 students included, 55 (39.3%) were colonized by S.aureus, and 3 (2,1%) by MRSA. The exposure to antibiotics in the last 3 months was lower in colonized students (12.3% vs. 25.9%, P=.03). Self-assessment showed that 56.4% of students almost never washed their hands before to attending to the first patient, and only 38.6% always washed after examining patients. More than a third (35.7%) ignored the hand hygiene protocol, and 38.6% had not received specific formation. Medical students should be included in hospital infection control programs. Hand hygiene training should be given to students before they begin their practices in the hospital. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Prevalence of multidrug-resistant, coagulase-positive Staphylococcus aureus in nasal carriage, food, wastewater and paper currency in Jalandhar city (north-western), an Indian state of Punjab.

PubMed

Kumar, Harsh; Palaha, Rajdeep; Kaur, Navreet; Ratnakar, Wankhede Swapnil; Sodi, Aakanksha; Kaur, Manmeet; Katiyar, Richa; Sharma, Mamta; Kaur, Charanpreet; Kumar, Virendra

2015-01-01

Development of multidrug-resistant pattern in the bacterial community is a major threat to the society. Staphylococcus aureus is perhaps the pathogen of the greatest concern because of its inherent virulence, its ability to cause a diverse array of life-threatening situations and capacity to adapt to different environmental conditions. The aims of this study is to investigate the multidrug-resistant pattern of the coagulase-positive S. aureus isolated from nasal carriage, food, paper currency and wastewater samples. We had also studied the multiple antibiotic resistance index and in vitro production of β-lactamase. The study had found out 130 coagulase-positive S. aureus strains isolated from total of 595 samples such as anterior nares of preschool children (195), hospital nurses (100), drivers (76), food (86), wastewater (3) and paper currency (135) (Indian rupee). The biotypes pattern were as follows; A > D > B > C> UT. Multiple antibiotic resistance (MAR) value clearly defines the multidrug-resistant pattern of the S. aureus among different sources. Statistical analysis (one-way ANOVA) of results obtained indicated that the difference in the antibiotic resistance observed in the 130 bacterial isolates against the 23 different antibiotics used in this study was statically significant (p < 0.01).

Prevalence of methicillin resistant Staphylococcus aureus [MRSA] colonization or carriage among health-care workers.

PubMed

Pathare, Nirmal A; Asogan, Harshini; Tejani, Sara; Al Mahruqi, Gaitha; Al Fakhri, Salma; Zafarulla, Roshna; Pathare, Anil V

2016-01-01

In Oman, the prevalence of health care associated methicillin resistant Staphylococcus aureus [HA-MRSA] is unknown. Therefore, to estimate the prevalence of HA-MRSA, we collected nasal swabs and swabs from cell phones on sterile polyester swabs and immediately inoculated on the mannitol salt agar containing oxacillin from medical students and hospital health care providers. Antibiotic susceptibility testing of the isolates was then performed using the Kirby Bauer's disc diffusion method. Additionally, a brief survey questionnaire was used to acquire demographic data. Amongst the 311 participants enrolled, nasal colonization with HA-MRSA was found in 47 individuals (15.1%, 95% confidence interval [CI]=11.1%, 19.1%). HA-MRSA was also isolated from the cell phone surfaces in 28 participants (9.0%, 95% CI=8.6%, 9.3%). 5 participants (1.6%) showed positive results both from their nasal swabs and from their cell phones. Antibiotic resistance to erythromycin [48%] and clindamycin [29%] was relatively high. 9.3% HA-MRSA isolates were vancomycin resistant [6.6% nasal carriage]. There was no statistically significant correlation between HA-MRSA isolates and the demographic characteristics or the risk factors namely gender, underlying co-morbidities like diabetes, hypertension, skin/soft tissue infections, skin ulcers/wounds, recent exposure to antibiotics, or hospital visits (p>0.05, Chi-square test). Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Plasmid-Encoded Transferable mecB-Mediated Methicillin Resistance in Staphylococcus aureus

PubMed Central

van Alen, Sarah; Idelevich, Evgeny A.; Schleimer, Nina; Seggewiß, Jochen; Mellmann, Alexander; Kaspar, Ursula; Peters, Georg

2018-01-01

During cefoxitin-based nasal screening, phenotypically categorized methicillin-resistant Staphylococcus aureus (MRSA) was isolated and tested negative for the presence of the mecA and mecC genes as well as for the SCCmec-orfX junction region. The isolate was found to carry a mecB gene previously described for Macrococcus caseolyticus but not for staphylococcal species. The gene is flanked by β-lactam regulatory genes similar to mecR, mecI, and blaZ and is part of an 84.6-kb multidrug-resistance plasmid that harbors genes encoding additional resistances to aminoglycosides (aacA-aphD, aphA, and aadK) as well as macrolides (ermB) and tetracyclines (tetS). This further plasmidborne β-lactam resistance mechanism harbors the putative risk of acceleration or reacceleration of MRSA spread, resulting in broad ineffectiveness of β-lactams as a main therapeutic application against staphylococcal infections. PMID:29350135

Control of nasal vasculature and airflow resistance in the dog.

PubMed Central

Lung, M A; Phipps, R J; Wang, J C; Widdicombe, J G

1984-01-01

Nasal vascular and airflow resistances have been measured in dogs, simultaneously on both sides separately. Vascular resistance was measured either by constant flow perfusion of the terminal branch of the maxillary artery (which supplies, via the sphenopalatine artery, the nasal septum, most of the turbinates and the nasal sinuses) or by measuring blood flow through this artery, maintained by the dog's own blood pressure. Airflow resistance was assessed by inserting balloon-tipped endotracheal catheters into the back of each nasal cavity via the nasopharynx, and measuring transnasal pressure at constant airflow through each side of the nose simultaneously. Preliminary experiments indicated that there was 5-10% collateral anastomosis between the two sides. Close-arterial injection of drugs showed different patterns of response. Adrenaline, phenylephrine, chlorpheniramine and low doses of prostaglandin F2 alpha increased vascular resistance and lowered airway resistance. Salbutamol, methacholine and histamine lowered vascular resistance and increased airway resistance. Dobutamine decreased airway resistance with a small increase in vascular resistance. Prostaglandins E1, E2 and F2 alpha (high dose) decreased both vascular and airway resistances. Substance P, eledoisin-related peptide and vasoactive intestinal polypeptide lowered vascular resistance with little change in airway resistance. The results are interpreted in terms of possible drug actions on precapillary resistance vessels, sinusoids and venules, and arteriovenous anastomoses. It is concluded that nasal airway resistance cannot be correlated with vascular resistance or blood flow, since the latter has a complex and ill-defined relationship with nasal vascular blood volume. PMID:6204040

Control of nasal vasculature and airflow resistance in the dog.

PubMed

Lung, M A; Phipps, R J; Wang, J C; Widdicombe, J G

1984-04-01

Nasal vascular and airflow resistances have been measured in dogs, simultaneously on both sides separately. Vascular resistance was measured either by constant flow perfusion of the terminal branch of the maxillary artery (which supplies, via the sphenopalatine artery, the nasal septum, most of the turbinates and the nasal sinuses) or by measuring blood flow through this artery, maintained by the dog's own blood pressure. Airflow resistance was assessed by inserting balloon-tipped endotracheal catheters into the back of each nasal cavity via the nasopharynx, and measuring transnasal pressure at constant airflow through each side of the nose simultaneously. Preliminary experiments indicated that there was 5-10% collateral anastomosis between the two sides. Close-arterial injection of drugs showed different patterns of response. Adrenaline, phenylephrine, chlorpheniramine and low doses of prostaglandin F2 alpha increased vascular resistance and lowered airway resistance. Salbutamol, methacholine and histamine lowered vascular resistance and increased airway resistance. Dobutamine decreased airway resistance with a small increase in vascular resistance. Prostaglandins E1, E2 and F2 alpha (high dose) decreased both vascular and airway resistances. Substance P, eledoisin-related peptide and vasoactive intestinal polypeptide lowered vascular resistance with little change in airway resistance. The results are interpreted in terms of possible drug actions on precapillary resistance vessels, sinusoids and venules, and arteriovenous anastomoses. It is concluded that nasal airway resistance cannot be correlated with vascular resistance or blood flow, since the latter has a complex and ill-defined relationship with nasal vascular blood volume.

Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from Intensive Care Unit Patients▿

PubMed Central

Snyder, James W.; Munier, Gina K.; Johnson, Charles L.

2010-01-01

This study compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay to culture by the use of BBL CHROMagar MRSA for the detection of MRSA in 627 nasal surveillance specimens collected from intensive care unit (ICU) patients. The PCR assay had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96.7%, 70.3%, and 100%, respectively. Nine of 19 false-positive PCR specimens grew methicillin-susceptible S. aureus (MSSA) from broth enrichment culture, of which two demonstrated evidence of mecA gene dropout. Compared to culture by the use of BBL CHROMagar MRSA, the BD GeneOhm MRSA PCR assay demonstrated sensitivity and specificity above 95% for the detection of MRSA nasal colonization and provided shorter turnaround time in generating positive and negative final results. PMID:20181916

Effectiveness of 5-Pyrrolidone-2-carboxylic Acid and Copper Sulfate Pentahydrate Association against Drug Resistant Staphylococcus Strains.

PubMed

Governa, Paolo; Miraldi, Elisabetta; De Fina, Gianna; Biagi, Marco

2016-04-01

Bacterial resistance is an ongoing challenge for pharmacotherapy and pharmaceutical chemistry. Staphylococcus aureus is the bacterial species which makes it most difficult to treat skin and soft tissue infections and it is seen in thousands of hospitalization cases each year. Severe but often underrated infectious diseases, such as complicated nasal infections, are primarily caused by MRSA and S. epidermidis too. With the aim of studying new drugs with antimicrobial activity and effectiveness on drug resistant Staphylococcus strains, our attention in this study was drawn on the activity of a new association between two natural products: 5-pyrrolidone-2-carboxylic acid (PCA), naturally produced by certain Lactobacillus species, and copper sulfate pentahydrate (CS). The antimicrobial susceptibility test was conducted taking into account 12 different Staphylococcus strains, comprising 6 clinical isolates and 6 resistant strains. PCA 4%, w/w, and CS 0.002%, w/w, association in distilled water solution was found to have bactericidal activity against all tested strains. Antimicrobial kinetics highlighted that PCA 4%, w/w, and CS 0.002% association could reduce by 5 log10 viable bacterial counts of MRSA and oxacillin resistant S. epidennidis in less than 5 and 3 minutes respectively. Microscopic investigations suggest a cell wall targeting mechanism of action. Being very safe and highly tolerated, the natural product PCA and CS association proved to be a promising antimicrobial agent to treat Staphylococcus related infections.

Effects of hypercapnia and hypoxia on nasal vasculature and airflow resistance in the anaesthetized dog.

PubMed Central

Lung, M A; Wang, J C

1986-01-01

The experiments were performed on anaesthetized dogs which breathed spontaneously or were artificially ventilated and paralysed. The spontaneous nasal arterial blood flow was measured on one side of the nose while nasal vascular resistance was determined on the other side simultaneously. Nasal arterial blood flow was measured by means of an electromagnetic flow sensor placed around the terminal branch of the internal maxillary artery, the main arterial supply to the nasal mucosa. Nasal vascular resistance was measured by constant-flow perfusion of the terminal branch of the internal maxillary artery. Nasal airway resistance was assessed by monitoring the transnasal pressure at constant airflow through each side of the nose simultaneously. Hypercapnic gas challenge (8% CO2, 30% O2 in N2) to the lungs increased nasal vascular resistance and decreased nasal airway resistance. Similar gas challenge to the nose did not affect nasal vascular resistance but decreased nasal airway resistance. Hypoxic gas challenge (6% O2 in N2) to the lungs did not affect the nasal vascular resistance but decreased nasal airway resistance only when the nasal vascular bed was under controlled perfusion. Similar gas challenge to the nose did not affect either nasal vascular or airway resistance. Arterial chemoreceptor stimulation by intracarotid injection of sodium cyanide increased nasal vascular resistance and decreased nasal airway resistance. The nasal vascular response to hypercapnia and arterial chemoreceptor stimulation was reflex in nature, being abolished by nasal sympathectomy. The nasal airway response to hypercapnia, hypoxia and arterial chemoreceptor stimulation was reflex in nature, being partially or completely abolished by nasal sympathectomy. Hypercapnia probably induced a local vasodilatatory effect on the capacitance vessels whereas hypoxia had no direct action on the vasculature. PMID:3091811

Methicillin-resistant Staphylococcus aureus in central Iowa wildlife.

PubMed

Wardyn, Shylo E; Kauffman, Lin K; Smith, Tara C

2012-10-01

Livestock and pets have been identified as carriers of Staphylococcus aureus; however, the role of wild animals as a reservoir of S. aureus strains has not yet been examined. We conducted a pilot study to determine the prevalence of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in 37 species of wild animals rehabilitated at a university clinic. Nasal, wing, wound, and cloacal swabs were collected. Of 114 animals, seven (6.1%) were MSSA-positive and three (2.6%) were MRSA-positive. The MRSA isolates were obtained from two eastern cottontail rabbits (Sylvilagus floridanus) and a Lesser Yellowlegs (Tringa flavipes), a migratory shorebird. Antibiotic resistance testing of the MRSA isolates revealed that two were additionally resistant to tetracycline and erythromycin, and the third isolate was also resistant to erythromycin, clindamycin, and levofloxacin. All three isolates were positive for the Panton-Valentine leukocidin (PVL) gene. Sequence typing of the staphylococcal protein A (spa) region revealed one MRSA isolate to be t002, whereas the other two MRSA isolates were found to be t008. Our results suggest that S. aureus, including MRSA, is being carried by wild animals, although at a low prevalence with the limited number of animals tested. Additional studies are needed to determine how this may impact human health.

Transmission of Methicillin-Resistant Staphylococcus aureus to Human Volunteers Visiting a Swine Farm.

PubMed

Angen, Øystein; Feld, Louise; Larsen, Jesper; Rostgaard, Klaus; Skov, Robert; Madsen, Anne Mette; Larsen, Anders Rhod

2017-12-01

Transmission of methicillin-resistant Staphylococcus aureus (MRSA) from animals to humans is of great concern due to the implications for human health and the health care system. The objective was to investigate the frequency and duration of MRSA carriage in human volunteers after a short-term exposure in a swine farm. The experimental study included 34 human volunteers staying 1 h in a MRSA-positive swine farm in four trials. In two of the trials, the influence of farm work involving pig contact was studied using a crossover design. The quantities of MRSA in nasal swabs, throat swabs, and air samples were measured at different time points and analyzed in relation to relevant covariates. This investigation showed that, overall, 94% of the volunteers acquired MRSA during the farm visit. Two hours after the volunteers left the stable, the nasal MRSA count had declined to unquantifiable levels in 95% of the samples. After 48 h, 94% of the volunteers were MRSA-negative. Nasal MRSA carriage was positively correlated to personal exposure to airborne MRSA and farm work involving pig contact and negatively correlated to smoking. No association was observed between MRSA carriage and face touching behavior, nasal methicillin-susceptible Staphylococcus aureus (MSSA) carriage, age, or gender. The increase in human MRSA carriage among the volunteers with pig contact seems to be dependent on the increased concentration of airborne MRSA of the surrounding air and not directly on physical contact with pigs. MRSA was not detected in any of the throat samples. IMPORTANCE The experimental approach made it possible to elucidate the contributions of airborne MRSA levels and farm work to nasal MRSA carriage in a swine farm. Short-term exposure to airborne MRSA poses a substantial risk for farm visitors to become nasal carriers, but the carriage is typically cleared within hours to a few days. The risk for short-term visitors to cause secondary transmissions of MRSA is most likely

Staphylococcus aureus disease and drug resistance in resource-limited countries in south and east Asia.

PubMed

Nickerson, Emma K; West, T Eoin; Day, Nicholas P; Peacock, Sharon J

2009-02-01

By contrast with high-income countries, Staphylococcus aureus disease ranks low on the public-health agenda in low-income countries. We undertook a literature review of S aureus disease in resource-limited countries in south and east Asia, and found that its neglected status as a developing world pathogen does not equate with low rates of disease. The incidence of the disease seems to be highest in neonates, its range of clinical manifestations is as broad as that seen in other settings, and the mortality rate associated with serious S aureus infection, such as bacteraemia, is as high as 50%. The prevalence of meticillin-resistant S aureus (MRSA) infection across much of resource-limited Asia is largely unknown. Antibiotic drugs are readily and widely available from pharmacists in most parts of Asia, where ease of purchase and frequent self-medication are likely to be major drivers in the emergence of drug resistance. In our global culture, the epidemiology of important drug-resistant pathogens in resource-limited countries is inextricably linked with the health of both developing and developed communities. An initiative is needed to raise the profile of S aureus disease in developing countries, and to define a programme of research to find practical solutions to the health-care challenges posed by this important global pathogen.

Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

PubMed

Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Methicillin-resistant Staphylococcus aureus nasal colonization in a level III neonatal intensive care unit: Incidence and risk factors.

PubMed

Giuffrè, Mario; Amodio, Emanuele; Bonura, Celestino; Geraci, Daniela M; Saporito, Laura; Ortolano, Rita; Corsello, Giovanni; Mammina, Caterina

2015-05-01

To describe epidemiologic features and identify risk factors for methicillin-resistant Staphylococcus aureus (MRSA) acquisition in a level III neonatal intensive care unit (NICU). A prospective, cohort study in a university-affiliated NICU with an infection control program including weekly nasal cultures of all neonates. Demographic, clinical, and microbiologic data were prospectively collected between June 2009 and June 2013. Molecular characterization of MRSA isolates was done by multilocus variable number tandem repeat fingerprinting, staphylococcal cassette chromosome mec typing, and on representative isolates by multilocus sequence typing and spa typing. Of 949 neonates, 217 (22.87%) had a culture growing MRSA, including 117 neonates testing positive at their first sampling. Of these latter infants, 96 (82.05%) were inborn and 59 (50.43%) had been transferred from the nursery. Length of stay and colonization pressure were strong independent predictors of MRSA acquisition. Among MRSA isolates, 7 sequence types were identified, with ST22-IVa, spa type t223, being the predominant strain. In an endemic area, early MRSA acquisition and high colonization pressure, likely related to an influx of colonized infants from a well-infant nursery, can support persistence of MRSA in NICUs. Surveillance, molecular tracking of strains, and reinforcement of infection control practices, involving well-infant nurseries in a comprehensive infection control program, could be helpful in containing MRSA transmission. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Coagulase-Positive Staphylococcus: Prevalence and Antimicrobial Resistance.

PubMed

Beça, Nuno; Bessa, Lucinda Janete; Mendes, Ângelo; Santos, Joana; Leite-Martins, Liliana; Matos, Augusto J F; da Costa, Paulo Martins

2015-01-01

Staphylococcus pseudintermedius is the most prevalent coagulase-positive Staphylococcus inhabitant of the skin and mucosa of dogs and cats, causing skin and soft tissue infections in these animals. In this study, coagulase-positive Staphylococcus species were isolated from companion animals, veterinary professionals, and objects from a clinical veterinary environment by using two particular culture media, Baird-Parker RPF agar and CHROMagar Staph aureus. Different morphology features of colonies on the media allowed the identification of the species, which was confirmed by performing a multiplex polymerase chain reaction (PCR). Among 23 animals, 15 (65.2%) harbored coagulase-positive Staphylococcus, being 12 Staphylococcus pseudintermedius carriers. Four out of 12 were methicillin-resistant S. pseudintermedius (MRSP). All veterinary professionals had coagulase-positive Staphylococcus (CoPS) species on their hands and two out of nine objects sampled harbored MRSP. The antimicrobial-resistance pattern was achieved for all isolates, revealing the presence of many multidrug-resistant CoPS, particularly S. pseudintermedius . The combined analysis of the antimicrobial-resistance patterns shown by the isolates led to the hypothesis that there is a possible crosscontamination and dissemination of S. aureus and S. pseudintermedius species between the three types of carriers sampled in this study that could facilitate the spread of the methicillin-resistance phenotype.

Risk Factors for Nasal Colonization by Methicillin-Resistant Staphylococci in Healthy Humans in Professional Daily Contact with Companion Animals in Portugal.

PubMed

Rodrigues, Ana Catarina; Belas, Adriana; Marques, Cátia; Cruz, Luís; Gama, Luís T; Pomba, Constança

2018-05-01

Methicillin-resistant staphylococci (MRS), namely Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), are opportunistic agents of great importance in human and veterinary medicine. The aims of this study were to investigate the frequency, persistence, and risk factors associated with nasal colonization by MRS in people in daily contact with animals in Portugal. Seventy-nine out of 129 (61.2%) participants were found to be colonized by, at least, one methicillin-resistant (MR) staphylococci species (MR Staphylococcus epidermidis [n = 68], MRSA [n = 19], MR Staphylococcus haemolyticus [n = 7], MRSP [n = 2], and other coagulase-negative staphylococci [n = 4]). Three lineages were identified among the MRSA isolates (n = 7): the major human healthcare clone in Portugal (ST22-t032-IV, n = 3), the livestock-associated MRSA (ST398-t108-V, n = 3), and the New York-/Japan-related clone (ST105-t002-II, n = 1). MRSP isolates belonged to the European clone ST71-II-III. We identified two risk factors for nasal colonization by MRS in healthy humans: (i) being a veterinary professional (veterinarian and veterinary nurse) (p < 0.0001, odds ratio [OR] = 6.369, 95% confidence interval [CI, 2.683-15.122]) and (ii) have contacted with one MRSA- or MRSP-positive animal (p = 0.0361, OR = 2.742, 95% CI [1.067-7.045]). The follow-up study revealed that the majority (85%) remain colonized. This study shows that MRS in veterinary clinical practice is a professional hazard and highlights the need to implement preventive measures to minimize spread.

Efficacy of two hydrogen peroxide vapour aerial decontamination systems for enhanced disinfection of meticillin-resistant Staphylococcus aureus, Klebsiella pneumoniae and Clostridium difficile in single isolation rooms.

PubMed

Ali, S; Muzslay, M; Bruce, M; Jeanes, A; Moore, G; Wilson, A P R

2016-05-01

Hydrogen peroxide vapour (HPV) disinfection systems are being used to reduce patients' exposure to hospital pathogens in the environment. HPV whole-room aerial disinfection systems may vary in terms of operating concentration and mode of delivery. To assess the efficacy of two HPV systems (HPS1 and HPS2) for whole-room aerial disinfection of single isolation rooms (SIRs). Ten SIRs were selected for manual terminal disinfection after patient discharge. Test coupons seeded with biological indicator (BI) organisms [∼10(6) colony-forming units (cfu) of meticillin-resistant Staphylococcus aureus (MRSA) or Klebsiella pneumoniae, or ∼10(5)cfu Clostridium difficile 027 spores] prepared in a soil challenge were placed at five locations per room. For each cycle, 22 high-frequency-touch surfaces in SIRs were sampled with contact plates (∼25cm(2)) before and after HPV decontamination, and BIs were assayed for the persistence of pathogens. Approximately 95% of 214 sites were contaminated with bacteria after manual terminal disinfection, with high numbers present on the SIR floor (238.0-352.5cfu), bed control panel (24.0-33.5cfu), and nurse call button (21.5-7.0cfu). Enhanced disinfection using HPV reduced surface contamination to low levels: HPS1 [0.25cfu, interquartile range (IQR) 0-1.13] and HPS2 (0.5cfu, IQR 0-2.0). Both systems demonstrated similar turnaround times (∼2-2.5h), and no differences were observed in the efficacy of the two systems against BIs (C. difficile ∼5.1log10 reduction; MRSA/K. pneumoniae ∼6.3log10 reduction). Despite different operating concentrations of hydrogen peroxide, MRSA persisted on 27% of coupons after HPV decontamination. Enhanced disinfection with HPV reduces surface contamination left by manual terminal cleaning, minimizing the risks of cross-contamination. The starting concentration and mode of delivery of hydrogen peroxide may not improve the efficacy of decontamination in practice, and therefore the choice of HPV system may

Occurrence and molecular characteristics of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius in an academic veterinary hospital.

PubMed

Ishihara, Kanako; Shimokubo, Natsumi; Sakagami, Akie; Ueno, Hiroshi; Muramatsu, Yasukazu; Kadosawa, Tsuyoshi; Yanagisawa, Chie; Hanaki, Hideaki; Nakajima, Chie; Suzuki, Yasuhiko; Tamura, Yutaka

2010-08-01

Recently, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) have been increasingly isolated from veterinarians and companion animals. With a view to preventing the spread of MRSA and MRSP, we evaluated the occurrence and molecular characteristics of each in a veterinary college. MRSA and MRSP were isolated from nasal samples from veterinarians, staff members, and veterinary students affiliated with a veterinary hospital. Using stepwise logistic regression, we identified two factors associated with MRSA carriage: (i) contact with an identified animal MRSA case (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 2.2 to 21.6) and (ii) being an employee (OR, 6.2; 95% CI, 2.0 to 19.4). The majority of MRSA isolates obtained from individuals affiliated with the veterinary hospital and dog patients harbored spa type t002 and a type II staphylococcal cassette chromosome mec (SCCmec), similar to the hospital-acquired MRSA isolates in Japan. MRSA isolates harboring spa type t008 and a type IV SCCmec were obtained from one veterinarian on three different sampling occasions and also from dog patients. MRSA carriers can also be a source of MRSA infection in animals. The majority of MRSP isolates (85.2%) carried hybrid SCCmec type II-III, and almost all the remaining MRSP isolates (11.1%) carried SCCmec type V. MRSA and MRSP were also isolated from environmental samples collected from the veterinary hospital (5.1% and 6.4%, respectively). The application of certain disinfection procedures is important for the prevention of nosocomial infection, and MRSA and MRSP infection control strategies should be adopted in veterinary medical practice.

Rifampicin treatment of canine pyoderma due to multidrug-resistant meticillin-resistant staphylococci: a retrospective study of 32 cases.

PubMed

De Lucia, Michela; Bardagi, Mar; Fabbri, Elisabetta; Ferreira, Diana; Ferrer, Lluis; Scarampella, Fabia; Zanna, Giordana; Fondati, Alessandra

2017-04-01

Rifampicin has received increased interest in veterinary dermatology because of its activity against multidrug-resistant meticillin-resistant staphylococci (MRS). There is limited knowledge about the efficacy and safety of rifampicin in dogs. To provide information on response to treatment and adverse effects in dogs treated with rifampicin for multidrug-resistant MRS pyoderma. Thirty two dogs treated with rifampicin for rifampicin-susceptible multidrug-resistant MRS pyoderma. Retrospective review of medical records, including alanine aminotransferase (ALT) and alkaline phosphatase (ALP) serum activity levels and total bilirubin concentrations, obtained before and throughout the treatment, was performed. Oral rifampicin as sole systemic antimicrobial therapy (median dose 5 mg/kg twice daily) was effective in 71.88% of cases. Topical antimicrobials were used in most cases. Median duration of rifampicin treatment was five weeks for superficial pyoderma and four weeks for deep pyoderma. Gastrointestinal signs were reported in 15% of treated dogs. Statistically significant increases of ALT (P = 0.045) and ALP (P = 0.0002) values after 3-4 weeks of treatment was observed. The median increase was equal to 0.3 and ×1.5 the upper limit of the reference ranges for ALT and ALP, respectively. Oral rifampicin combined with topical antimicrobials can be considered an effective therapeutic option for canine superficial and deep pyoderma caused by rifampicin-susceptible multidrug-resistant MRS. Liver enzyme induction might be the most important cause of ALT and ALP increase associated with rifampicin therapy in dogs. © 2016 ESVD and ACVD.

Emergence of Nasal Carriage of ST80 and ST152 PVL+ Staphylococcus aureus Isolates from Livestock in Algeria

PubMed Central

Agabou, Amir; Ouchenane, Zouleikha; Ngba Essebe, Christelle; Khemissi, Salim; Chehboub, Mohamed Tedj Eddine; Chehboub, Ilyes Bey; Dunyach-Remy, Catherine

2017-01-01

The spread of toxinogenic Staphylococcus aureus is a public health problem in Africa. The objectives of the study were to investigate the rate of S. aureus nasal carriage and molecular characteristics of these strains in livestock and humans in three Algerian provinces. Nasal samples were collected from camels, horses, cattle, sheep and monkeys, as well as humans in contact with them. S. aureus isolates were genotyped using DNA microarray. The rate of S. aureus nasal carriage varied between species: camels (53%), humans and monkeys (50%), sheep (44.2%), horses (15.2%) and cattle (15%). Nine methicillin-resistant S. aureus (MRSA) isolates (7.6%) were identified, isolated from camels and sheep. The S. aureus isolates belonged to 15 different clonal complexes. Among them, PVL+ (Panton–Valentine Leukocidin) isolates belonging to ST80-MRSA-IV and ST152-MSSA were identified in camels (n = 3, 13%) and sheep (n = 4, 21.1%). A high prevalence of toxinogenic animal strains was noted containing TSST-1- (22.2%), EDINB- (29.6%) and EtD- (11.1%) encoding genes. This study showed the dispersal of the highly human pathogenic clones ST152-MSSA and ST-80-MRSA in animals. It suggests the ability of some clones to cross the species barrier and jump between humans and several animal species. PMID:28946704

Superantigens Modulate Bacterial Density during Staphylococcus aureus Nasal Colonization

PubMed Central

Xu, Stacey X.; Kasper, Katherine J.; Zeppa, Joseph J.; McCormick, John K.

2015-01-01

Superantigens (SAgs) are potent microbial toxins that function to activate large numbers of T cells in a T cell receptor (TCR) Vβ-specific manner, resulting in excessive immune system activation. Staphylococcus aureus possesses a large repertoire of distinct SAgs, and in the context of host-pathogen interactions, staphylococcal SAg research has focused primarily on the role of these toxins in severe and invasive diseases. However, the contribution of SAgs to colonization by S. aureus remains unclear. We developed a two-week nasal colonization model using SAg-sensitive transgenic mice expressing HLA-DR4, and evaluated the role of SAgs using two well-studied stains of S. aureus. S. aureus Newman produces relatively low levels of staphylococcal enterotoxin A (SEA), and although we did not detect significant TCR-Vβ specific changes during wild-type S. aureus Newman colonization, S. aureus Newman Δsea established transiently higher bacterial loads in the nose. S. aureus COL produces relatively high levels of staphylococcal enterotoxin B (SEB), and colonization with wild-type S. aureus COL resulted in clear Vβ8-specific T cell skewing responses. S. aureus COL Δseb established consistently higher bacterial loads in the nose. These data suggest that staphylococcal SAgs may be involved in regulating bacterial densities during nasal colonization. PMID:26008236

Molecular epidemiology and virulence characteristics of Staphylococcus aureus nasal colonization in medical laboratory staff: comparison between microbiological and non-microbiological laboratories.

PubMed

Xie, Xiaoying; Dai, Xinlu; Ni, Lijia; Chen, Baiji; Luo, Zhaofan; Yao, Yandan; Wu, Xiquan; Li, Hongyu; Huang, Songyin

2018-03-12

Medical laboratory staff are a high-risk population for colonization of Staphylococcus aureus (S. aureus) due to direct and dense contact with the pathogens; however, there is limited information about this colonization. This study sought to determine the prevalence and molecular characteristics of nasal colonization by S. aureus in medical laboratory staff in Guangzhou, southern China, and to compare the differences between microbiological laboratory (MLS) and non-microbiological laboratory (NMLS) staff. S. aureus colonization was assessed by nasal swab cultures from 434 subjects, including 130 MLSs and 304 NMLSs from 33 hospitals in Guangzhou. All S. aureus isolates underwent the antimicrobial susceptibility test, virulence gene detection and molecular typing. The overall prevalence of S. aureus carriage was 20.1% (87/434), which was higher in MLSs than in NMLSs (26.2% vs. 17.4%, P < 0.05), while the prevalence of Methicillin-resistant S. aureus (MRSA) was similar. Living with hospital staff was associated with S. aureus carriage. The majority of the isolates harboured various virulence genes, and those in MLSs appeared less resistant to antibiotics and more virulent than their counterparts. A total of 37 different spa types were detected; among these, t338, t437, t189 and t701 were the most frequently encountered types. T338 was the main spa type contributing to nasal colonization Methicillin-sensitive S. aureus (MSSA) (13.0%), and t437-SCCmec IV was predominant in MRSA isolates (40%). These findings provide insight into the risk factors, molecular epidemiology and virulence gene profiles of S. aureus nasal carriage among the medical laboratory staff in Guangzhou.

Methicillin-resistant Staphylococcus argenteus misidentified as methicillin-resistant Staphylococcus aureus emerging in western Sweden.

PubMed

Tång Hallbäck, Erika; Karami, Nahid; Adlerberth, Ingegerd; Cardew, Sofia; Ohlén, Maria; Engström Jakobsson, Hedvig; Svensson Stadler, Liselott

2018-05-17

Two strains included in a whole-genome sequencing project for methicillin-resistant Staphylococcus aureus (MRSA) were identified as non-Staphylococcus aureus when the sequences were analysed using the bioinformatics software ALEX (www.1928diagnostics.com, Gothenburg, Sweden). Sequencing of the sodA gene of these strains identified them as Staphylococcus argenteus. The collection of MRSA in western Sweden was checked for additional strains of this species. A total of 18 strains of S. argenteus isolated between 2011 and December 2017 were identified.

Sustainable reduction of nasal colonization and hand contamination with Staphylococcus aureus in food handlers, 2002-2011.

PubMed

Ho, J; Boost, M; O'Donoghue, M

2015-06-01

A longitudinal study of nasal colonization and hand contamination of food handlers with Staphylococcus aureus commenced in 2002 prior to the outbreak of severe acute respiratory syndrome. In the follow-up in 2003 when hygiene measures were strictly implemented, significant reductions in carriage were observed. To investigate if this change was sustained, nasal and hand carriage rates were compared between the earlier studies and a further sampling in 2011. The initial nasal carriage rate was 35% and hand contamination 41·2%, decreasing to 23·5% and 11·6%, respectively in 2003 (P < 0·001). In 2011, nasal carriage was similar to 2003 (22·9%), while hand contamination dropped further to 3·7% (P < 0·001). Spa-typing revealed 39 types in 2002 and 42 in 2011. This study reveals that the marked reduction in colonization had been sustained. This may be attributed to reduced opportunities for spread due to enhanced hygiene and reinforces its importance for control of disease.

Incidence of Staphylococcus aureus nasal colonization and soft tissue infection among high school football players.

PubMed

Lear, Aaron; McCord, Gary; Peiffer, Jeffrey; Watkins, Richard R; Parikh, Arpan; Warrington, Steven

2011-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections have been documented with increasing frequency in both team and individual sports in recent years. It also seems that the level of MRSA skin and soft tissue infections in the general population has increased. One hundred ninety athletes from 6 local high school football teams were recruited for this prospective observational study to document nasal colonization and the potential role this plays in skin and soft tissue infections in football players and, in particular, MRSA infections. Athletes had nasal swabs done before their season started, and they filled out questionnaires regarding potential risk factors for skin and soft tissue infections. Those enrolled in the study were then observed over the course of the season for skin and soft tissue infections. Those infected had data about their infections collected. One hundred ninety of 386 available student athletes enrolled in the study. Forty-four of the subjects had nasal colonization with methicillin-susceptible S. aureus, and none were colonized with MRSA. There were 10 skin and soft tissue infections (8 bacterial and 2 fungal) documented over the course of the season. All were treated as outpatients with oral or topical antibiotics, and none were considered serious. Survey data from the preseason questionnaire showed 21% with skin infection, 11% with methicillin-susceptible S. aureus, and none with MRSA infection during the past year. Three reported a remote history of MRSA infection. We documented an overall skin infection rate of 5.3% among high school football players over a single season. Our results suggest that skin and soft tissue infection may not be widespread among high school athletes in northeast Ohio.

Self-sampling is appropriate for detection of Staphylococcus aureus: a validation study

PubMed Central

2012-01-01

Background Studies frequently use nasal swabs to determine Staphylococcus aureus carriage. Self-sampling would be extremely useful in an outhospital research situation, but has not been studied in a healthy population. We studied the similarity of self-samples and investigator-samples in nares and pharynxes of healthy study subjects (hospital staff) in the Netherlands. Methods One hundred and five nursing personnel members were sampled 4 times in random order after viewing an instruction paper: 1) nasal self-sample, 2) pharyngeal self-sample, 3) nasal investigator-sample, and 4) pharyngeal investigator-sample. Results For nasal samples, agreement is 93% with a kappa coefficient of 0.85 (95% CI 0.74-0.96), indicating excellent agreement, for pharyngeal samples agreement is 83% and the kappa coefficient is 0.60 (95% CI 0.43-0.76), indicating good agreement. In both sampling sites self-samples even detected more S. aureus than investigator-samples. Conclusions This means that self-samples are appropriate for detection of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. PMID:23137281

Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days

PubMed Central

Nadimpalli, Maya; Rinsky, Jessica L; Wing, Steve; Hall, Devon; Stewart, Jill; Larsen, Jesper; Nachman, Keeve E; Love, Dave C; Pierce, Elizabeth; Pisanic, Nora; Strelitz, Jean; Harduar-Morano, Laurel; Heaney, Christopher D

2015-01-01

Objectives This study aimed to evaluate the persistence of nasal carriage of Staphylococcus aureus, methicillin-resistant S. aureus and multidrug-resistant S. aureus over 14 days of follow-up among industrial hog operation workers in North Carolina. Methods Workers anticipating at least 24 h away from work were enrolled June–August 2012. Participants self-collected a nasal swab and completed a study journal on the evening of day 1, and each morning and evening on days 2–7 and 14 of the study. S. aureus isolated from nasal swabs were assessed for antibiotic susceptibility, spa type and absence of the scn gene. Livestock association was defined by absence of scn. Results Twenty-two workers provided 327 samples. S. aureus carriage end points did not change with time away from work (mean 49 h; range >0–96 h). Ten workers were persistent and six were intermittent carriers of livestock-associated S. aureus. Six workers were persistent and three intermittent carriers of livestock-associated multidrug-resistant S. aureus. One worker persistently carried livestock-associated methicillin-resistant S. aureus. Six workers were non-carriers of livestock-associated S. aureus. Eighty-two per cent of livestock-associated S. aureus demonstrated resistance to tetracycline. A majority of livestock-associated S. aureus isolates (n=169) were CC398 (68%) while 31% were CC9. No CC398 and one CC9 isolate was detected among scn-positive isolates. Conclusions Nasal carriage of livestock-associated S. aureus, multidrug-resistant S. aureus and methicillin-resistant S. aureus can persist among industrial hog operation workers over a 14-day period, which included up to 96 h away from work. PMID:25200855

Prevalence of and risk factors for community-acquired methicillin-resistant and methicillin-sensitive staphylococcus aureus colonization in children seen in a practice-based research network.

PubMed

Fritz, Stephanie A; Garbutt, Jane; Elward, Alexis; Shannon, William; Storch, Gregory A

2008-06-01

We sought to define the prevalence of and risk factors for methicillin-resistant Staphylococcus aureus nasal colonization in the St Louis pediatric population. Children from birth to 18 years of age presenting for sick and well visits were recruited from pediatric practices affiliated with a practice-based research network. Nasal swabs were obtained, and a questionnaire was administered. We enrolled 1300 participants from 11 practices. The prevalence of methicillin-resistant S aureus nasal colonization varied according to practice, from 0% to 9% (mean: 2.6%). The estimated population prevalence of methicillin-resistant S aureus nasal colonization for the 2 main counties of the St Louis metropolitan area was 2.4%. Of the 32 methicillin-resistant S aureus isolates, 9 (28%) were health care-associated types and 21 (66%) were community-acquired types. A significantly greater number of children with community-acquired methicillin-resistant S aureus were black and were enrolled in Medicaid, in comparison with children colonized with health care-associated methicillin-resistant S aureus. Children with both types of methicillin-resistant S aureus colonization had increased contact with health care, compared with children without colonization. Methicillin-sensitive S aureus nasal colonization ranged from 9% to 31% among practices (mean: 24%). The estimated population prevalence of methicillin-sensitive S aureus was 24.6%. Risk factors associated with methicillin-sensitive S aureus colonization included pet ownership, fingernail biting, and sports participation. Methicillin-resistant S aureus colonization is widespread among children in our community and includes strains associated with health care-associated and community-acquired infections.

Infective endocarditis of native valve after anterior nasal packing.

PubMed

Jayawardena, Suriya; Eisdorfer, Jacob; Indulkar, Shalaka; Zarkaria, Muhammad

2006-01-01

We present a case report of a patient who was previously treated for spontaneous epistaxis with a petroleum jelly gauze (0.5 in x 72 in) anterior nasal packing filled with an antibiotic ointment, along with prophylactic oral clindamycin. The patient presented with fever and hypotension 3 days after the nasal packing. Her blood cultures grew methicillin-resistant Staphylococcus aureus and the transesophageal echocardiography showed vegetation on the atrial surface of the posterior mitral valve leaflet, confirming the diagnosis of bacterial endocarditis attributable to nasal packing. Several case reports discuss toxic shock syndrome after nasal packing, but none describe endocarditis of the native heart valves subsequent to anterior nasal packing. Current guidelines on endocarditis prophylaxis produced by the American Heart Association, European Cardiac Society, and British Cardiac Society together with published evidence do not recommend endocarditis prophylaxis for patients with native heart valves undergoing anterior nasal packing.

Methicillin-resistant Staphylococcus aureus in palliative care: A prospective study of Methicillin-resistant Staphylococcus aureus prevalence in a hospital-based palliative care unit.

PubMed

Schmalz, Oliver; Strapatsas, Tobias; Alefelder, Christof; Grebe, Scott Oliver

2016-07-01

Methicillin-resistant Staphylococcus aureus is a common organism in hospitals worldwide and is associated with morbidity and mortality. However, little is known about the prevalence in palliative care patients. Furthermore, there is no standardized screening protocol or treatment for patients for whom therapy concentrates on symptom control. Examining the prevalence of methicillin-resistant Staphylococcus aureus in palliative care patients as well as the level of morbidity and mortality. We performed a prospective study where methicillin-resistant Staphylococcus aureus screening was undertaken in 296 consecutive patients within 48 h after admission to our palliative care unit. Medical history was taken, clinical examination was performed, and the Karnofsky Performance Scale and Palliative Prognostic Score were determined. Prevalence of Methicillin-resistant Staphylococcus aureus was compared to data of general hospital patients. In total, 281 patients were included in the study having a mean age of 69.7 years (standard deviation = 12.9 years) and an average Karnofsky Performance Scale between 30% and 40%. The mean length of stay was 9.7 days (standard deviation = 7.6 days). A total of 24 patients were methicillin-resistant Staphylococcus aureus positive on the first swab. Median number of swabs was 2. All patients with a negative methicillin-resistant Staphylococcus aureus swab upon admission remained Methicillin-resistant Staphylococcus aureus negative in all subsequent swabs. Our study suggests that the prevalence of Methicillin-resistant Staphylococcus aureus among patients in an in-hospital palliative care unit is much higher than in other patient populations. © The Author(s) 2016.

Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days.

PubMed

Nadimpalli, Maya; Rinsky, Jessica L; Wing, Steve; Hall, Devon; Stewart, Jill; Larsen, Jesper; Nachman, Keeve E; Love, Dave C; Pierce, Elizabeth; Pisanic, Nora; Strelitz, Jean; Harduar-Morano, Laurel; Heaney, Christopher D

2015-02-01

This study aimed to evaluate the persistence of nasal carriage of Staphylococcus aureus, methicillin-resistant S. aureus and multidrug-resistant S. aureus over 14 days of follow-up among industrial hog operation workers in North Carolina. Workers anticipating at least 24 h away from work were enrolled June-August 2012. Participants self-collected a nasal swab and completed a study journal on the evening of day 1, and each morning and evening on days 2-7 and 14 of the study. S. aureus isolated from nasal swabs were assessed for antibiotic susceptibility, spa type and absence of the scn gene. Livestock association was defined by absence of scn. Twenty-two workers provided 327 samples. S. aureus carriage end points did not change with time away from work (mean 49 h; range >0-96 h). Ten workers were persistent and six were intermittent carriers of livestock-associated S. aureus. Six workers were persistent and three intermittent carriers of livestock-associated multidrug-resistant S. aureus. One worker persistently carried livestock-associated methicillin-resistant S. aureus. Six workers were non-carriers of livestock-associated S. aureus. Eighty-two per cent of livestock-associated S. aureus demonstrated resistance to tetracycline. A majority of livestock-associated S. aureus isolates (n=169) were CC398 (68%) while 31% were CC9. No CC398 and one CC9 isolate was detected among scn-positive isolates. Nasal carriage of livestock-associated S. aureus, multidrug-resistant S. aureus and methicillin-resistant S. aureus can persist among industrial hog operation workers over a 14-day period, which included up to 96 h away from work. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Survey of nasal carriage of Staphylococcus aureus and intestinal parasites among food handlers working at Gondar University, Northwest Ethiopia

PubMed Central

2012-01-01

Background Food borne disease are major health problems in developing countries like Ethiopia. Food handlers with poor personal hygiene working in food establishments could be potential sources of disease due to pathogenic organisms. However; information on disease prevalence among food handlers working in University of Gondar cafeterias are very scarce. The aim of this study is to assess the prevalence of nasal carriage of Staphylococcus aureus, their drug resistance pattern and prevalence of intestinal parasites among food handlers working in University of Gondar student’s cafeterias. Method A cross sectional study was conducted among food handlers working in University of Gondar student’s cafeterias. A pretested structured questionnaire was used for collecting data. Nasal swab and stool were investigated for S. aureus and intestinal parasites; respectively as per the standard of the laboratory methods. Results Among 200 food handlers, females comprised 171(85.5%). The majority (67.5%) of the food-handlers were young adults aged 18–39 years. One hundred ninety four (97%) of the food handlers were not certified as a food handler. Forty one (20.5%) food handlers were positive for nasal carriage of S. aureus, of these 4(9.8%) was resistant for methicilin. Giardia lamblia was the most prevalent parasites 22 (11%), followed by Ascaris lumbricoides 13(6.5%), Entamoeba histolytica 12 (6%), Strongyloides stercolaris (0.5), Taenia species 1(0.5%) and Schistosoma mansoni 1(0.5%). Conclusion The finding stressed that food handlers with different pathogenic micro organisms may pose significant risk on the consumers. Higher officials should implement food handler’s training on food safety, periodic medical checkup and continuous monitoring of personal hygiene of food handlers. PMID:23031414

Survey of nasal carriage of Staphylococcus aureus and intestinal parasites among food handlers working at Gondar University, Northwest Ethiopia.

PubMed

Dagnew, Mulat; Tiruneh, Moges; Moges, Feleke; Tekeste, Zinaye

2012-10-02

Food borne disease are major health problems in developing countries like Ethiopia. Food handlers with poor personal hygiene working in food establishments could be potential sources of disease due to pathogenic organisms. However; information on disease prevalence among food handlers working in University of Gondar cafeterias are very scarce. The aim of this study is to assess the prevalence of nasal carriage of Staphylococcus aureus, their drug resistance pattern and prevalence of intestinal parasites among food handlers working in University of Gondar student's cafeterias. A cross sectional study was conducted among food handlers working in University of Gondar student's cafeterias. A pretested structured questionnaire was used for collecting data. Nasal swab and stool were investigated for S. aureus and intestinal parasites; respectively as per the standard of the laboratory methods. Among 200 food handlers, females comprised 171(85.5%). The majority (67.5%) of the food-handlers were young adults aged 18-39 years. One hundred ninety four (97%) of the food handlers were not certified as a food handler. Forty one (20.5%) food handlers were positive for nasal carriage of S. aureus, of these 4(9.8%) was resistant for methicilin. Giardia lamblia was the most prevalent parasites 22 (11%), followed by Ascaris lumbricoides 13(6.5%), Entamoeba histolytica 12 (6%), Strongyloides stercolaris (0.5), Taenia species 1(0.5%) and Schistosoma mansoni 1(0.5%). The finding stressed that food handlers with different pathogenic micro organisms may pose significant risk on the consumers. Higher officials should implement food handler's training on food safety, periodic medical checkup and continuous monitoring of personal hygiene of food handlers.

Host innate inflammatory factors and staphylococcal protein A influence the duration of human Staphylococcus aureus nasal carriage.

PubMed

Cole, A L; Muthukrishnan, G; Chong, C; Beavis, A; Eade, C R; Wood, M P; Deichen, M G; Cole, A M

2016-11-01

Human Staphylococcus aureus (SA) nasal carriage provides a reservoir for the dissemination of infectious strains; however, factors regulating the establishment and persistence of nasal colonization are mostly unknown. We measured carriage duration and nasal fluid inflammatory markers after nasally inoculating healthy participants with their previously isolated SA strains. Out of 15 studies, 10 resulted in rapid clearance (9±6 days) that corresponded with upregulated chemokines, growth factors, and predominantly Th1-type cytokines, but not interleukin (IL)-17. Nasal SA persistence corresponded with elevated baseline levels of macrophage inflammatory protein-1β, IL-1β, and IL-6, no induction of inflammatory factors after inoculation, and decreased IL-1 receptor antagonist/IL-1β ratio. SA-expressed staphylococcal protein A (SpA) levels correlated positively with carriage duration. Competitive inoculation studies revealed that isogenic SpA knockout (ΔSpA) strains were cleared faster than wild type only in participants with upregulated inflammatory markers after inoculation. The remaining participants did not mount an inflammatory response and did not clear either strain. ΔSpA strains demonstrated lower growth rates in carrier nasal fluids and lower survival rates when incubated with neutrophils. Collectively, the presented studies identify innate immune effectors that cooperatively modulate nasal carriage duration, and confirm SpA as a bacterial codeterminant of SA nasal carriage.

Host innate inflammatory factors and staphylococcal protein A influence the duration of human Staphylococcus aureus nasal carriage

PubMed Central

Cole, Amy L.; Muthukrishnan, Gowrishankar; Chong, Christine; Beavis, Ashley; Eade, Colleen R.; Wood, Matthew P.; Deichen, Michael G.; Cole, Alexander M.

2016-01-01

Human Staphylococcus aureus (SA) nasal carriage provides a reservoir for the dissemination of infectious strains; however, factors regulating the establishment and persistence of nasal colonization are mostly unknown. We measured carriage duration and nasal fluid inflammatory markers after nasally inoculating healthy participants with their previously isolated SA strains. Ten out of 15 studies resulted in rapid clearance (9±6 days) that corresponded with upregulated chemokines, growth factors, and predominantly Th1-type cytokines, but not IL-17. Nasal SA persistence corresponded with elevated baseline levels of MIP-1β, IL-1β, and IL-6, no induction of inflammatory factors post-inoculation, and decreased IL-1RA:IL-1β ratio. SA-expressed staphylococcal protein A (SpA) levels correlated positively with carriage duration. Competitive inoculation studies revealed that isogenic SpA knockout (ΔSpA) strains were cleared faster than wild-type only in participants with upregulated inflammatory markers post-inoculation. The remaining participants did not mount an inflammatory response and did not clear either strain. ΔSpA strains demonstrated lower growth rates in carrier nasal fluids and lower survival rates when incubated with neutrophils. Collectively, the presented studies identify innate immune effectors that cooperatively modulate nasal carriage duration, and confirm SpA as a bacterial co-determinant of SA nasal carriage. PMID:26838052

Threat of drug resistant Staphylococcus aureus to health in Nepal

PubMed Central

2014-01-01

Background Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. Methods This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibiotic susceptibility profiles. Clinical samples were cultured and Staphylococcus aureus was identified using standard microbiological methods recommended by the American Society for Microbiology (ASM). Methicillin resistance was confirmed using cefoxitin and oxacillin disks. Inducible clindamycin resistance was identified using D-zone test. Results From the processed samples, 306 isolates of Staphylococcus aureus were recovered. All the isolates were susceptible to vancomycin and teicoplanin. Methicillin resistance was observed in 43.1% of isolates while inducible clindamycin resistance in 12.4% of the isolates. Conclusions The results of our study reveals that rates of resistance to commonly prescribed antibiotics in Staphylococcus aureus clinical isolates is high. In particular, rate of methicillin resistance is alarming, prompting concern on the rational use of antibiotics and vigilant laboratory-based surveillance of resistance rates in Nepal. PMID:24655316

Cost-effectiveness of national mandatory screening of all admissions to English National Health Service hospitals for meticillin-resistant Staphylococcus aureus: a mathematical modelling study.

PubMed

Robotham, Julie V; Deeny, Sarah R; Fuller, Chris; Hopkins, Susan; Cookson, Barry; Stone, Sheldon

2016-03-01

In December, 2010, National Health Service (NHS) England introduced national mandatory screening of all admissions for meticillin-resistant Staphylococcus aureus (MRSA). We aimed to assess the effectiveness and cost-effectiveness of this policy, from a regional or national health-care decision makers' perspective, compared with alternative screening strategies. We used an individual-based dynamic transmission model parameterised with national MRSA audit data to assess the effectiveness and cost-effectiveness of admission screening of patients in English NHS hospitals compared with five alternative strategies (including no screening, checklist-activated screening, and high-risk specialty-based screening), accompanied by patient isolation and decolonisation, over a 5 year time horizon. We evaluated strategies for different NHS hospital types (acute, teaching, and specialist), MRSA prevalence, and transmission potentials using probabilistic sensitivity analyses. Compared with no screening, mean cost per quality-adjusted life-year (QALY) of screening all admissions was £89,000-148,000 (range £68,000-222,000), and this strategy was consistently more costly and less effective than alternatives for all hospital types. At a £30,000/QALY willingness-to-pay threshold and current prevalence, only the no-screening strategy was cost effective. The next best strategies were, in acute and teaching hospitals, targeting of high-risk specialty admissions (30-40% chance of cost-effectiveness; mean incremental cost-effectiveness ratios [ICERs] £45,200 [range £35,300-61,400] and £48,000/QALY [£34,600-74,800], respectively) and, in specialist hospitals, screening these patients plus risk-factor-based screening of low-risk specialties (a roughly 20% chance of cost-effectiveness; mean ICER £62,600/QALY [£48,000-89,400]). As prevalence and transmission increased, targeting of high-risk specialties became the optimum strategy at the NHS willingness-to-pay threshold (£30,000/QALY

Recommendations for approaches to meticillin-resistant staphylococcal infections of small animals: diagnosis, therapeutic considerations and preventative measures.: Clinical Consensus Guidelines of the World Association for Veterinary Dermatology.

PubMed

Morris, Daniel O; Loeffler, Anette; Davis, Meghan F; Guardabassi, Luca; Weese, J Scott

2017-06-01

Multiple drug resistance (MDR) in staphylococci, including resistance to the semi-synthetic penicillinase-resistant penicillins such as meticillin, is a problem of global proportions that presents serious challenges to the successful treatment of staphylococcal infections of companion animals. The objective of this document is to provide harmonized recommendations for the diagnosis, prevention and treatment of meticillin-resistant staphylococcal infections in dogs and cats. The authors served as a Guideline Panel (GP) and reviewed the literature available prior to September 2016. The GP prepared a detailed literature review and made recommendations on selected topics. The World Association of Veterinary Dermatology (WAVD) provided guidance and oversight for this process. A draft of the document was presented at the 8th World Congress of Veterinary Dermatology (May 2016) and was then made available via the World Wide Web to the member organizations of the WAVD for a period of three months. Comments were solicited and posted to the GP electronically. Responses were incorporated by the GP into the final document. Adherence to guidelines for the diagnosis, laboratory reporting, judicious therapy (including restriction of use policies for certain antimicrobial drugs), personal hygiene, and environmental cleaning and disinfection may help to mitigate the progressive development and dissemination of MDR staphylococci. © 2017 The Authors. Veterinary Dermatology published by John Wiley & Sons Ltd on behalf of the ESVD and ACVD.

Comparison of Genotypes and Enterotoxin Genes Between Staphylococcus aureus Isolates from Blood and Nasal Colonizers in a Korean Hospital

PubMed Central

Peck, Kyong Ran; Baek, Jin Yang; Song, Jae-Hoon

2009-01-01

In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness. PMID:19654937

Staphylococcus aureus nasal decolonization in joint replacement surgery reduces infection.

PubMed

Hacek, Donna M; Robb, William J; Paule, Suzanne M; Kudrna, James C; Stamos, Van Paul; Peterson, Lance R

2008-06-01

Surgical site infections (SSIs) with Staphylococcus aureus are a recognized adverse event of hip and knee replacements. We evaluated the impact of a program to detect S. aureus nasal carriers before surgery with preoperative decolonization (using mupirocin twice daily for 5 days prior to surgery) of carriers. Nasal swab samples were obtained from patients prior to surgery from 8/1/2003 through 2/28/2005. Samples were tested using real-time PCR technology to detect S. aureus. The group that developed S. aureus SSI was compared to a combined concurrent and historical control for one year following the operation. S. aureus caused 71% of SSIs in the combined control groups. Of the 1495 surgical candidates evaluated, 912 (61.0%) were screened for S. aureus; 223 of those screened (24.5%) were positive and then decolonized with mupirocin. Among the 223 positive and decolonized patients, three (1.3%) developed a SSI. Among the 689 screen-negative patients, four (0.6%) developed SSIs for an overall rate of 0.77%. Among the 583 control patients who were not screened or decolonized, 10 (1.7%) developed S. aureus SSIs. SSIs from other organisms were 0.44% and 0.69%, respectively. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

A prospective cohort study of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage in neonates: the role of maternal carriage and phenotypic and molecular characteristics

PubMed Central

Lin, Jialing; Wu, Chuanan; Yan, Chunrong; Ou, Qianting; Lin, Dongxin; Zhou, Junli; Ye, Xiaohua; Yao, Zhenjiang

2018-01-01

Background Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), in mothers can cause serious outcomes in neonates. We aimed to elucidate the associations of S. aureus and MRSA carriage between mothers and neonates. Methods A prospective cohort study was conducted between August and November 2015 in two hospitals in Shenzhen, China. Chinese pregnant women and their neonates who met the inclusion criteria were included in this study; samples and relevant information were collected. We assessed maternal–neonatal associations by using Poisson regression models. Results Overall, 1834 mothers and their neonates were included in this study. The prevalence of isolate carriage among the mothers was as follows: S. aureus (nasal, 25.8%; vaginal, 7.3%; and nasal and vaginal, 3.3%) and MRSA (nasal, 5.7%; vaginal, 1.7%; and nasal and vaginal, 0.5%). The incidences of S. aureus and MRSA carriage among neonates were 3.3% and 0.8%, respectively. Of the 21 maternal–neonatal pairs with S. aureus carriage, 14 were concordant pairs with the same phenotypic and molecular characteristics. After adjustment, the relative risks and 95% confidence intervals (CIs) between the S. aureus carriage of neonates and nasal S. aureus carriage, vaginal S. aureus carriage, and both nasal and vaginal S. aureus carriage of mothers were 2.8 (95% CI, 1.6–4.8), 7.1 (95% CI, 4.1–12.4), and 9.6 (95% CI, 4.2–22.4), respectively. Conclusion S. aureus carriage in mothers increases the risk for neonates. PMID:29731644

[Systematic screening for methicillin-resistant Staphylococcus aureus (MRSA) in the nasal cavities of patients hospitalized in the dermatology departments of the Saint-Louis Hospital].

PubMed

Gener, G; Dupuy, A; Rouveau, M; Claisse, J-P; Casin, I; Dubertret, L; Morel, P; Simon, F; Viguier, M

2008-12-01

In a bid to combat methicillin-resistant Staphylococcus aureus (MRSA) more efficiently in our department, we performed a study to 1) clarify the MRSA carriage rate in patients hospitalized in the department; 2) evaluate the rate of MRSA acquisition during hospitalization; 3) describe the MRSA carrier profile; 4) study the morbidity and mortality associated with MRSA. We conducted a three-month prospective study in all patients hospitalized for more than 24hours in the dermatology department of the Saint-Louis Hospital. Nasal swab cultures were performed on the day of admission, once a week thereafter and on the day of discharge. Clinical and epidemiological data were individually reviewed by means of a standardized questionnaire. In 310 patients, the prevalence of nasal MRSA carriage at admission was 6.5%. During hospitalization, 1.9% of our patients became colonized with MRSA. MRSA carriers were significantly older than non-carriers and had been hospitalized more frequently over the previous 12 months, principally in intensive care or in intermediate or long-term care facilities, and erosive and/or ulcerated dermatitis was more common in this population. Of the 27 patients colonized with MRSA, only three had MRSA infections, and these were successfully treated with antibiotics. The observed rate of MRSA carriage was close to that seen in intensive care units (7%). While systematic screening for MRSA in patients with erosive and/or ulcerated dermatitis would allow detection of twice as many cases of MRSA than the usual screening recommendations, this would be associated with little tangible benefit and high costs, and we therefore decided not to change the usual MRSA screening politic in our dermatology department.

Presence, distribution and molecular epidemiology of multi-drug-resistant Gram-negative bacilli from medical personnel of intensive care units in Tianjin, China, 2007-2015.

PubMed

Liu, H; Fei, C N; Zhang, Y; Liu, G W; Liu, J; Dong, J

2017-06-01

Multi-drug-resistant Gram-negative bacteria (MDRGNB) have become an important cause of nosocomial infection in intensive care units (ICUs). To investigate the molecular epidemiology of MDRGNB isolated from medical personnel (MP) and non-medical personnel (NMP) at 69 ICUs in Tianjin, China. From April 2007 to October 2015, 2636 nasal and hand swab samples from 1185 MP and 133 NMP were cultured for GNB (including MDRGNB), meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The susceptibilities of GNB to 14 antimicrobial agents were determined, and 80 MDRGNB were characterized using pulsed-field gel electrophoresis (PFGE) and dendrogram analysis. In total, 301 GNB were identified in 269 MP, including 109 MDRGNB isolates in 104 MP. Forty-two GNB were isolated from 39 NMP, which included 20 NMP with MDRGNB. Overall, 8.8% of MP were colonized with MDRGNB, which greatly exceeded colonization rates with MRSA (0.9%) and VRE (0.1%). Three pairs of Klebsiella pneumoniae and one pair of Enterobacter aerogenes were indistinguishable from each other, but the majority of isolate tests had distinct PFGE profiles. The prevalence of MDRGNB was high among ICU MP in Tianjin, and greatly exceeded that of VRE and MRSA. There was no difference in the rates of nasal carriage of MDRGNB between MP and NMP, but NMP were significantly more likely to have hand colonization with MDRGNB. PFGE profiles showed that there was only limited sharing of strains of MDR E. aerogenes and K. pneumoniae between personnel. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Nasal carriage and antimicrobial susceptibility of Staphylococcus aureus in healthy preschool children in Ujjain, India.

PubMed

Pathak, Ashish; Marothi, Yogyata; Iyer, Rama V; Singh, Binita; Sharma, Megha; Eriksson, Bo; Macaden, Ragini; Lundborg, Cecilia Stålsby

2010-12-29

There is increasing evidence that community acquired S. aureus infections are spreading among healthy children. Nasal colonization with S. aureus plays pivotal role in the increasing prevalence of resistant community acquired S. aureus infections worldwide. A regular surveillance system is important in ensuring quality of patient care. The aim of the study was to assess the prevalence of and the factors associated with nasal carriage of S. aureus and its antibiotic sensitivity pattern among healthy children in Ujjain, India. A prospective study was done in paediatric outpatient clinics of R.D. Gardi medical college Ujjain, India. Healthy children from 1 month to 59 months of age were included. Information on previously known risk factors for nasal colonization was collected using a pre-tested questionnaire. Swabs from anterior nares were collected and transported in Amies transport media with charcoal and cultured on 5% sheep blood agar. Antibiotic sensitivity tests were performed using Kirby Bauer's disc diffusion method according to performance standards of Clinical and Laboratory Standard Institute guidelines. Of the 1,562 children from 1-month up-to five years of age included in the study 98 children tested positive for nasal carriage of S. aureus. The prevalence of nasal carriage of S. aureus was 6.3% (95% CI 5.1-7.5) out of which 16.3% (95% CI 8.9-23.8) were methicillin-resistant S. aureus (MRSA). The factors associated with nasal carriage were "child attending preschool" (OR 4.26, 95% CI 2.25-8.03; P = 0.007) or "school" (OR 3.02, 95% CI 1.27-7.18; P < 0.001) and "family size more than 10 members" (OR 2.76 95% CI 1.06-7.15; P = 0.03). The sensitivity pattern of isolated S. aureus showed resistance to commonly used oral antibiotics while resistance to glycopeptides was not noted. We found a relatively low rate of nasal carriage of S. aureus in children below five years when compared to children of older age groups in India. Yet, prevalence of MRSA was

Staphylococcus aureus nasal carriage among outpatients attending primary health care centers: a comparative study of two cities in Saudi Arabia and Egypt.

PubMed

Abou Shady, Hala M; Bakr, Alaa Eldin A; Hashad, Mahmoud E; Alzohairy, Mohammad A

2015-01-01

Epidemiological and molecular data on community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) are still scarce in both Egypt and Saudi Arabia. There is almost no data regarding methicillin resistant Staphylococcus aureus (MRSA) prevalence in both countries. This study was conducted to investigate the prevalence and molecular epidemiology of S. aureus and MRSA nasal carriage among outpatients attending primary health care centers in two big cities in both countries. A total of 206 nasal swabs were obtained, 103 swabs from each country. S. aureus isolates were characterized by antibiotic susceptibility, presence of mecA and PVL genes, SCCmec-typing and spa typing, the corresponding Multi locus sequence typing clonal complex was assigned for each spa type based on Ridom StaphType database. MRSA was detected in 32% of the Egyptian outpatients while it was found in 25% of the Saudi Arabian outpatients. All MRSA isolates belonged to SCCmec type V and IVa, where some isolates in Saudi Arabia remained nontypeable. Surprisingly PVL(+) isolates were low in frequency: 15% of MRSA Egyptian isolates and 12% of MRSA isolates in Saudi Arabia. Two novel spa types were detected t11839 in Egypt, and t11841 in Saudi Arabia. We found 8 spa types among 20 isolates from Egypt, and 12 spa types out of 15 isolates from Saudi Arabia. Only two spa types t008 and t223 coexisted in both countries. Four clonal complexes (CC5, CC8, CC22, and CC80) were identified in both Egypt and Saudi Arabia. However, the data collected lacked a representation of isolates from different parts of each country as only one health center from each country was included, it still partially illustrates the CA-MRSA situation in both countries. In conclusion a set of control measures is required to prevent further increase in MRSA prevalence. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

[Vancomycin-resistant Staphylococcus aureus].

PubMed

Rodríguez, Carlos Andrés; Vesga, Omar

2005-12-01

The evolution and molecular mechanisms of vancomycin resistance in Staphylococcus aureus were reviewed. Case reports and research studies on biochemestry, electron microscopy and molecular biology of Staphylococcus aureus were selected from Medline database and summarized in the following review. After almost 40 years of successful treatment of S. aureus with vancomycin, several cases of clinical failures have been reported (since 1997). S. aureus strains have appeared with intermediate susceptibility (MIC 8-16 microg/ml), as well as strains with heterogeneous resistance (global MIC < or =4 microg/ml), but with subpopulations of intermediate susceptibility. In these cases, resistance is mediated by cell wall thickening with reduced cross linking. This traps the antibiotic before it reaches its major target, the murein monomers in the cell membrane. In 2002, a total vancomycin resistant strain (MIC > or =32 microg/ml) was reported with vanA genes from Enterococcus spp. These genes induce the change of D-Ala-D-Ala terminus for D-Ala-D-lactate in the cell wall precursors, leading to loss of affinity for glycopeptides. Vancomycin resistance in S. aureus has appeared; it is mediated by cell wall modifications that trap the antibiotic before it reaches its action site. In strains with total resistance, Enterococcus spp. genes have been acquired that lead to modification of the glycopeptide target.

Identification and characterization of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus pettenkoferi from a small animal clinic.

PubMed

Weiss, Sonja; Kadlec, Kristina; Fessler, Andrea T; Schwarz, Stefan

2013-12-27

The aim of this study was to isolate and characterize methicillin-resistant staphylococci (MRS) in a small animal clinic and to investigate their distribution and possible transmission. Swabs (n=72) were taken from hospitalized pets, the environment and employees of a small animal clinic and screened for the presence of MRS. The staphylococcal species was confirmed biochemically or by 16S rDNA sequencing. Susceptibility to antimicrobial agents was tested by broth dilution. The presence of mecA and other resistance genes was confirmed by PCR. Molecular typing of the isolates followed standard procedures. In total, 34 MRS belonging to the four species Staphylococcus aureus (n=5), Staphylococcus epidermidis (n=21), Staphylococcus haemolyticus (n=6) or Staphylococcus pettenkoferi (n=2) were isolated. All isolates were multidrug-resistant with resistance to at least three classes of antimicrobial agents. Among the five methicillin-resistant S. aureus (MRSA) isolates, four belonged to the clonal complex CC398; two of them were isolated from cats, the remaining two from pet cages. Overall, the MRS isolates differed in their characteristics, except for one S. epidermidis clone (n=9) isolated from hospitalized cats without clinical staphylococcal infections, pet cages, the clinic environment as well as from a healthy employee. This MRSE clone was resistant to 10 classes of antimicrobial agents, including aminocyclitols, β-lactams, fluoroquinolones, lincosamides, macrolides, phenicols, pleuromutilins, sulfonamides, tetracyclines and trimethoprim. These findings suggest a possible transmission of specific MRS isolates between animal patients, employees and the clinic environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Antibiotic resistance and molecular characteristics of Staphylococcus aureus isolated from backyard-raised pigs and pig workers.

PubMed

Momoh, Asabe Halimat; Kwaga, Jacob K P; Bello, Mohammed; Sackey, Anthony K B; Larsen, Anders Rhod

2018-04-19

Staphylococcus aureus is a commensal and pathogenic bacterium with impact on public health and livestock industry. The study investigated nasal carriage, antibiotic resistance, and molecular characterization of S. aureus in pigs and pig workers. Nasal swabs from 300 backyard-raised pigs and 101 pig workers were used for the study. Resulting isolates were confirmed using MALDI-TOF MS, tested for antibiotic resistance, and three different multiplex PCRs were used to detect enterotoxin, mecA, spaA, scn, and pvl genes. spa typing was used to annotate the isolates into MLST clonal complexes (CC). Structured questionnaire was used to access possible risk factors for S. aureus carriage. The prevalence of S. aureus in pigs and pig workers were 5.3 and 12.9%, respectively. The isolates were resistant to beta-lactams (97%), tetracycline (62%), sulfonamide (52%), aminoglycoside (20.6%), fluoroquinolone (24%), and mupirocin (3.4%). Twenty seven (93%) of the isolates carried scn, 7(24%) pvl, and 12 (41%) enterotoxin genes, respectively. Questionnaire survey showed medical-related occupation of household members was associated (p < 0.5) with S. aureus carriage. This study suggests the presence of human multidrug resistant strains of S. aureus, high carriage of pvl, and enterotoxin genes, and CC5, CC15, and CC152 were the CC-groups shared among pigs and pig workers.

[Change in drug resistance of Staphylococcus aureus].

PubMed

Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

2013-11-01

To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P < 0.05). In the dynamic observation of drug resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Evidence that Intraspecific Trait Variation among Nasal Bacteria Shapes the Distribution of Staphylococcus aureus

PubMed Central

Libberton, Ben; Coates, Rosanna E.

2014-01-01

Nasal carriage of Staphylococcus aureus is a risk factor for infection, yet the bacterial determinants required for carriage are poorly defined. Interactions between S. aureus and other members of the bacterial flora may determine colonization and have been inferred in previous studies by using correlated species distributions. However, traits mediating species interactions are often polymorphic, suggesting that understanding how interactions structure communities requires a trait-based approach. We characterized S. aureus growth inhibition by the culturable bacterial aerobe consortia of 60 nasal microbiomes, and this revealed intraspecific variation in growth inhibition and that inhibitory isolates clustered within communities that were culture negative for S. aureus. Across microbiomes, the cumulative community-level growth inhibition was negatively associated with S. aureus incidence. To fully understand the ecological processes structuring microbiomes, it will be crucial to account for intraspecific variation in the traits that mediate species interactions. PMID:24980973

Nasal colonization of Staphylococcus aureus colonal complex 5: Prevalence, influencing factors, and phenotypic and molecular characteristics in pregnant Chinese women.

PubMed

Lin, Jialing; Wu, Chuanan; Ou, Qianting; Lin, Dongxin; Zhang, Ting; Bai, Chan; Zheng, Haoqu; Ye, Jiaping; Wang, Xiaojie; Li, Ying; Ye, Xiaohua; Yao, Zhenjiang

2017-10-01

Colonal complex 5 (CC5) has been referred to as the most pandemic community-associated Staphylococcus aureus in most Asian countries. However, few studies have focused on CC5 isolates in pregnant women. The aim of this study was to determine the prevalence and phenotypic and molecular characteristics of S aureus and methicillin-resistant S aureus (MRSA) CC5 nasal colonization in pregnant Chinese women. We performed a cross-sectional study between August and November 2015 in 2 hospitals in Shenzhen, China. Pregnant women were asked to complete questionnaires, and nasal swabs were collected. Log-binomial regression models were used to explore factors influencing S aureus and MRSA nasal colonization between the CC5 and non-CC5 or non-S aureus groups. Polymerase chain reaction assays were used to detect the molecular characteristics of isolates. Overall, 2,172 pregnant women were included in this study. The prevalence of S aureus and MRSA was 25.60% (n = 556) and 5.62% (n = 122), respectively. The multilocus sequence typing of S aureus isolates was diversified. A lower frequency of daily handwashing (<7) and weekly bathing (<7) were risk factors for the prevalence of S aureus (adjusted prevalence ratio [aPR], 1.13; 95% confidence interval [CI], 1.03-1.41 and aPR, 1.22; 95% CI, 1.03-1.45) and MRSA (aPR, 1.96; 95% CI, 1.23-3.14 and aPR, 1.47; 95% CI, 1.21-2.44) nasal colonization in the CC5 groups of pregnant women. The prevalence of S aureus and MRSA nasal colonization was moderate. The molecular characteristics of S aureus and MRSA isolates indicated possible cross-transmission among multiple resources. A higher frequency of daily handwashing and weekly bathing significantly decreased the prevalence of S aureus and MRSA CC5 nasal colonization in the pregnant women. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Risk factors for anti-MRSA drug resistance.

PubMed

Abe, Yasuhisa; Shigemura, Katsumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

2012-11-01

Meticillin-resistant Staphylococcus aureus (MRSA)-related infections have recently been spreading and are difficult to control, partly because affected patients are frequently in a poor condition. This study retrospectively investigated recent MRSA-related infections focusing on the relationship between clinical risk factors and anti-MRSA drug resistance. The patients with MRSA-related infections in Kobe University Hospital (Kobe, Japan) in 2009 were enrolled in the study. The relationships between various clinical risk factors as well as MRSA bacterial DNA concentration with minimum inhibitory concentrations (MICs) of anti-MRSA drugs were examined. In total, 44 patients were enrolled in the study and MRSA was isolated from blood (23 patients), urine (12 patients) and nasal secretions (9 patients). There was only one resistant strain to linezolid (LZD) among the anti-MRSA drugs tested, and this strain was considered staphylococcal cassette chromosome mec (SCCmec) type IIa from phage open-reading frame typing analyses. Statistical analyses showed that MRSA bacterial DNA concentration, cancer and use of a respirator, respectively, had a significant relationship with the MICs of LZD (P=0.0058) and arbekacin (ABK) (P=0.0003), of quinupristin/dalfopristin (Q/D) (P=0.0500) and ABK (P=0.0133), and of Q/D (P=0.0198) and vancomycin (P=0.0036). In conclusion, bacterial DNA concentration, cancer and use of a respirator were found to be significant risk factors for lower susceptibilities to anti-MRSA drugs; one strain was resistant to LZD. We suggest that further investigation and surveillance for MRSA-related infection are necessary for preventing the spread of MRSA-related infections. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Risk and outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia among patients admitted with and without MRSA nares colonization.

PubMed

Marzec, Natalie S; Bessesen, Mary T

2016-04-01

The risk of nosocomial methicillin-sensitive Staphylococcus aureus bacteremia in patients with nasal colonization on admission is 3-fold higher than in patients who are not colonized. Limited data on this question have been reported for methicillin-resistant S aureus (MRSA). This is an observational cohort study of patients admitted to a tertiary care medical center from October 1, 2007-September 30, 2013, who underwent active screening for nasal colonization with MRSA. There were 29,371 patients who underwent screening for nasal MRSA colonization; 3,262 (11%) were colonized with MRSA. There were 32 cases of MRSA bacteremia among colonized patients, for an incidence of 1%. Thirteen cases of bacteremia occurred in non-MRSA-colonized patients, for an incidence of 0.05%. The odds of developing MRSA bacteremia for patients who were nasally colonized with MRSA compared with those who were not colonized were 19.89. There was no difference between colonized and noncolonized subjects with bacteremia in all-cause mortality at 30 days or 1 year. In a setting with active screening for MRSA, the risk of MRSA bacteremia is 19.89-fold higher among colonized than noncolonized patients. Published by Elsevier Inc.

Comparison of BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR versus the CHROMagar MRSA Assay for Screening Patients for the Presence of MRSA Strains▿

PubMed Central

Boyce, John M.; Havill, Nancy L.

2008-01-01

We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay with the CHROMagar MRSA assay for the detection of MRSA in 286 nasal surveillance specimens. Compared with the CHROMagar MRSA assay, PCR had sensitivity, specificity, positive predictive value, and negative predictive values of 100%, 98.6%, 95.8%, and 100%, respectively. The mean PCR turnaround time was 14.5 h. PMID:18032616

Methicillin-Resistant Staphylococcus aureus Infections: A Comprehensive Review and a Plastic Surgeon's Approach to the Occult Sites.

PubMed

Hunter, Cedric; Rosenfield, Lorne; Silverstein, Elena; Petrou-Zeniou, Panayiota

2016-08-01

Up to 20 percent of the general population is persistently colonized with Staphylococcus aureus, and 1 to 3 percent of the population is colonized with community-acquired methicillin-resistant S. aureus. Currently, the knowledge of methicillin-resistant Staphylococcus aureus carriage sites other than the nose, and their effect on surgical site infections in cosmetic surgery, is lacking. A comprehensive literature review using the PubMed database to analyze prevalence, anatomical carrier sites, current screening and decontamination protocols and guidelines, and methicillin-resistant S. aureus in cosmetic surgery was performed. The senior author's (L.R.) methicillin-resistant S. aureus infection experience and prevention protocols were also reviewed. Nasal swabs detect only 50.5 percent of methicillin-resistant S. aureus colonization, and broad screening has noted the presence of methicillin-resistant S. aureus in the ear canal and umbilicus. Decolonization protocols within the orthopedic and cardiothoracic surgery literature have reduced rates of methicillin-resistant S. aureus surgical-site infections. There are no decolonization guidelines for plastic surgeons. Since instituting their decolonization protocol, the authors have had no cases of methicillin-resistant S. aureus infection in nearly 1000 cosmetic surgery procedures. There are very limited, if any, Level I or II data regarding methicillin-resistant S. aureus screening and decolonization. As the sequelae of a surgical-site infection can be disastrous, expert opinions recommend that plastic surgeons vigorously address methicillin-resistant S. aureus colonization and infection. The authors have developed and recommend a simple decolonization protocol that includes treatment of the umbilicus, ear canal, and nares to limit surgical-site infection and improve surgical outcomes.

Institutional prescreening for detection and eradication of methicillin-resistant Staphylococcus aureus in patients undergoing elective orthopaedic surgery.

PubMed

Kim, David H; Spencer, Maureen; Davidson, Susan M; Li, Ling; Shaw, Jeremy D; Gulczynski, Diane; Hunter, David J; Martha, Juli F; Miley, Gerald B; Parazin, Stephen J; Dejoie, Pamela; Richmond, John C

2010-08-04

Surgical site infection has been identified as one of the most important preventable sources of morbidity and mortality associated with medical treatment. The purpose of the present study was to evaluate the feasibility and efficacy of an institutional prescreening program for the preoperative detection and eradication of both methicillin-resistant and methicillin-sensitive Staphylococcus aureus in patients undergoing elective orthopaedic surgery. Data were collected prospectively during a single-center study. A universal prescreening program, employing rapid polymerase chain reaction analysis of nasal swabs followed by an eradication protocol of intranasal mupirocin and chlorhexidine showers for identified carriers, was implemented. Surgical site infection rates were calculated and compared with a historical control period immediately preceding the start of the screening program. During the study period, 7019 of 7338 patients underwent preoperative screening before elective surgery, for a successful screening rate of 95.7%. One thousand five hundred and eighty-eight (22.6%) of the patients were identified as Staphylococcus aureus carriers, and 309 (4.4%) were identified as methicillin-resistant Staphylococcus aureus carriers. A significantly higher rate of surgical site infection was observed among methicillin-resistant Staphylococcus aureus carriers (0.97%; three of 309) compared with noncarriers (0.14%; seven of 5122) (p = 0.0162). Although a higher rate of surgical site infection was also observed among methicillin-sensitive Staphylococcus aureus carriers (0.19%; three of 1588) compared with noncarriers, this difference did not achieve significance (p = 0.709). Overall, thirteen cases of surgical site infection were identified during the study period, for an institutional infection rate of 0.19%. This rate was significantly lower than that observed during the control period (0.45%; twenty-four cases of surgical site infection among 5293 patients) (p = 0

Clinical effectiveness of rapid tests for methicillin resistant Staphylococcus aureus (MRSA) in hospitalized patients: a systematic review

PubMed Central

2011-01-01

Background Methicillin resistant Staphylococcus aureus (MRSA) are often resistant to multiple classes of antibiotics. The research objectives of this systematic review were to evaluate the clinical effectiveness of polymerase chain reaction (PCR) versus chromogenic agar for MRSA screening, and PCR versus no screening for several clinical outcomes, including MRSA colonization and infection rates. Methods An electronic literature search was conducted on studies evaluating polymerase chain reaction techniques and methicillin (also spelled meticillin) resistant Staphylococcus aureus that were published from 1993 onwards using Medline, Medline In-Process & Other Non-Indexed Citations, BIOSIS Previews, and EMBASE. Due to the presence of heterogeneity in the selected studies, the clinical findings of individual studies were described. Results Nine studies that compared screening for MRSA using PCR versus screening using chromogenic agar in a hospital setting, and two studies that compared screening using PCR with no or targeted screening were identified. Some studies found lower MRSA colonization and acquisition, infection, and transmission rates in screening with PCR versus screening with chromogenic agar, and the turnaround time for screening test results was lower for PCR. One study reported a lower number of unnecessary isolation days with screening using PCR versus screening with chromogenic agar, but the proportion of patients isolated was similar between both groups. The turnaround time for test results and number of isolation days were lower for PCR versus chromogenic agar for MRSA screening. Conclusions The use of PCR for MRSA screening demonstrated a lower turnaround time and number of isolation days compared with chromogenic agar. Given the mixed quality and number of studies (11 studies), gaps remain in the published literature and the evidence remains insufficient. In addition to screening, factors such as the number of contacts between healthcare workers and

Does Nasal Carriage of Staphylococcus aureus Increase the Risk of Postoperative Infections After Elective Spine Surgery: Do Most Infections Occur in Carriers?

PubMed

Adogwa, Owoicho; Vuong, Victoria D; Elsamadicy, Aladine A; Lilly, Daniel T; Desai, Shyam A; Khalid, Syed; Cheng, Joseph; Bagley, Carlos A

2018-05-14

Wound infections after adult spinal deformity surgery place a high toll on patients, providers, and the healthcare system. Staphylococcus aureus is a common cause of postoperative wound infections, and nasal colonization by this organism may be an important factor in the development of surgical site infections (SSIs). The aim is to investigate whether post-operative surgical site infections after elective spine surgery occur at a higher rate in patients with methicillin-resistant S. aureus (MRSA) nasal colonization. Consecutive patients undergoing adult spinal deformity surgery between 2011-2013 were enrolled. Enrolled patients were followed up for a minimum of 3 months after surgery and received similar peri-operative infection prophylaxis. Baseline characteristics, operative details, rates of wound infection, and microbiologic data for each case of post-operative infection were gathered by direct medical record review. Local vancomycin powder was used in all patients and sub-fascial drains were used in the majority (88%) of patients. 1200 operative spine cases were performed for deformity between 2011 and 2013. The mean ± standard deviation age and body mass index were 62.08 ± 14.76 years and 30.86 ± 7.15 kg/m 2 , respectively. 29.41% had a history of diabetes. All SSIs occurred within 30 days of surgery, with deep wound infections accounting for 50% of all SSIs. Of the 34 (2.83%) cases of SSIs that were identified, only 1 case occurred in a patient colonized with MRSA. Our study suggests that the preponderance of SSIs occurred in patients without nasal colonization by methicillin-resistant S. aureus. Future prospective multi-institutional studies are needed to corroborate our findings. Copyright © 2018 Elsevier Inc. All rights reserved.

Frequent isolation of methicillin resistant Staphylococcus aureus (MRSA) ST398 among healthy pigs in Portugal.

PubMed

Conceição, Teresa; de Lencastre, Hermínia; Aires-de-Sousa, Marta

2017-01-01

Although livestock-associated ST398 methicillin-resistant Staphylococcus aureus (MRSA) has been widely reported in different geographic regions, MRSA carriage studies among healthy pigs in Portugal are very limited. In total, 101 swine nasal samples from two Portuguese farms were screened for MRSA. In addition five swine workers (including one veterinary and one engineer) and four household members were nasally screened. The isolates were characterized by spa typing, SCCmec typing and MLST. All isolates were tested for antimicrobial susceptibility, presence of mecA and mecC genes, and virulence determinants. MRSA prevalence in swine was 99% (100/101), 80% (4/5) in swine workers and 25% (1/4) in household members. All isolates belonged to ST398 distributed over two spa types-t011 (57%) and t108 (42%). SCCmec type V was present in most of the isolates (n = 95; 82%) while 21 isolates amplified the mecA gene only and were classified as nontypeable. The majority of the isolates were resistant to tetracycline (100%), clindamycin (97%), erythromycin (96%), chloramphenicol (84%) and gentamycin (69%). Notably, 12% showed resistance to quinupristin-dalfopristin (MICs 3-8 μg/mL). Beta-hemolysin (81%) and gamma-hemolysin (74%) were the unique virulence determinants detected. None of the isolates harboured PVL or mecC gene. This study showed a massive occurrence of ST398-MRSA in two independent swine farms, highlighting its establishment among healthy pigs in Portugal.

Isolation of bacterial skin flora of healthy sheep, with comparison between frequent and minimal human handling.

PubMed

Haarstad, Amy C; Eisenschenk, Melissa C; Heinrich, Nicole A; Weese, J Scott; McKeever, Patrick J

2014-06-01

Few data are available regarding skin bacterial flora of healthy sheep and meticillin-resistant Staphylococcus carriage. To compare skin, ear and mucosal bacterial populations between minimally and frequently handled sheep; to determine whether the frequency of meticillin-resistant Staphylococcus aureus varied between groups. One hundred and three healthy feedlot and show sheep from eight farms. Swabs were collected from the dorsum, right ear and right nostril of each sheep. Two groups from each farm were evaluated, except from one farm, which had only one group. Bacterial isolates were identified to the genus or species level using phenotypic analysis or matrix-associated laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing and spa typing were performed on isolates of S. aureus. Sixteen bacterial genera were identified and 11 staphylococcal species, including S. aureus. The skin and mucosal bacterial flora were compared between the groups. The only statistically significant difference in bacteria was Streptococcus spp. on the dorsum (P = 0.0088), with carriage being more common in frequently handled sheep. Antimicrobial susceptibility testing did not find meticillin-resistant S. aureus. There was no significant difference in S. aureus carriage in the ear (P = 0.33), nostril (P = 0.43) or dorsum (P = 0.053) between frequently and minimally handled sheep. The S. aureus isolates belonged to six different spa types. Three were of the ST398 lineage. Sheep are a potential source of livestock-associated meticillin-sensitive Staphylococcus aureus ST398. © 2014 ESVD and ACVD.

Lung and pharyngeal abscess caused by enterotoxin G- and I-producing Staphylococcus aureus.

PubMed

Barnett, S Y; Hattotuwa, K L; Teare, L

2012-05-01

We report a particularly serious case of extensive meticillin sensitive Staphylococcal lung and pharyngeal abscess. Our patient had no significant risk factors for severe infection. The detection of enterotoxin G and I here suggest that when present together, these toxins work synergistically to produce a more virulent strain of Staphylococcus aureus. Copyright © 2011. Published by Elsevier Ltd.

MICROBIOLOGICAL ASSESSMENT OF LETTUCE SALADS AND ANTIMICROBIAL RESISTANCE OF STAPHYLOCOCCUS SPP.

PubMed

Guimarães César, Josi; Madruga Peres, Andriele; Pereira das Neves, Caroline; Tupiniquim Freitas de Abreu, Érica; Fagundes de Mello, Jozi; Nunes Moreira, Ângela; Lameiro Rodrigues, Kelly

2015-11-01

self-service restaurants in which food is served ready to be consumed are liable to have some products contaminated by pathogenic microorganisms causing food-transmitted diseases. evaluates the microbiological quality of lettuce salads in restaurants in Pelotas RS Brazil by counts of thermo-tolerant coliforms, E. coli, Staphylococcus spp. and detection of Salmonella spp. Antimicrobial resistance of Staphylococcus spp. isolates are also assessed. thirty-six samples of lettuce salads were collected from nine restaurants and thermotolerant coliforms, Escherichia coli and Staphylococcus spp. were quantified, coupled to a research on Salmonella spp., following methodology by the Bacteriological Analytical Manual. Staphylococcus spp. isolates underwent antimicrobial resistance test by the disc-diffusion method. results showed that 61.1% of the salad samples contained more thermotolerant coliforms than allowed by Brazilian legislation and E. coli was confirmed in 5.6% of the samples. Positive and negative coagulase Staphylococcus occurred respectively in 5.6% and 77.8% of isolates, but no sample had Salmonella spp. Further, 56.7% of the thirty isolates of Staphylococcus spp. tested were resistant to penicillin; 46.7% to oxacillin; 26.7% to erythromycin and 23.3% were multi- resistant. inadequate quality of the salad was due to pathogenic microorganisms, while Staphylococcus spp. isolates had a high percentage of antimicrobial resistance. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Genotypes and enterotoxicity of Staphylococcus aureus isolated from the hands and nasal cavities of flight-catering employees.

PubMed

Hatakka, M; Björkroth, K J; Asplund, K; Mäki-Petäys, N; Korkeala, H J

2000-11-01

Hand and nasal samples of flight-catering staff were collected from 1995 to 1997 to find employees carrying Staphylococcus aureus. Altogether 153 hand samples and 136 nose samples were taken. Nasal sampling showed a higher prevalence of S. aureus among food handlers (29%) than hand sampling (9%). A high proportion of the strains (46%) were enterotoxigenic, and a considerable amount of food handlers carried enterotoxigenic S. aureus, 6% and 12% according to hand and nasal sampling, respectively. Pulsed-field gel electrophoresis macrorestriction profiles revealed a total of 32 different types associated with the 35 employees carrying S. aureus. In most cases, the same type colonized both the hand and nose of a person. Despite the wide variety of types found, one strain colonized five persons and the second most common strain was associated with four food handlers. The predominant toxin produced was B, which was produced by the most common strain. The results showed that nasal sampling is a good way to detect S. aureus carriers, whereas hand sampling may fail to reveal carriers. The high proportion of enterotoxigenic strains show that a food handler harboring S. aureus must be considered a potential source of enterotoxigenic strains for airline meals.

Community-Acquired Methicillin-Resistant "Staphylococcus aureus": Considerations for School Nurses

ERIC Educational Resources Information Center

Alex, Aniltta; Letizia, MariJo

2007-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) is a disease-causing organism that has been present in hospital settings since the 1960s. However, a genetically distinct strain of MRSA, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA), has emerged in recent years in community settings among healthy…

Investigation of the Potential for Mutational Resistance to XF-73, Retapamulin, Mupirocin, Fusidic Acid, Daptomycin, and Vancomycin in Methicillin-Resistant Staphylococcus aureus Isolates during a 55-Passage Study ▿

PubMed Central

Farrell, David J.; Robbins, Marion; Rhys-Williams, William; Love, William G.

2011-01-01

XF-73 is a dicationic porphyrin drug with rapid Gram-positive antibacterial activity currently undergoing clinical trials for the nasal decolonization of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). In multistep (55-passage) resistance selection studies in the presence of subinhibitory concentrations of XF-73, retapamulin, mupirocin, fusidic acid, and vancomycin against four Network on Antimicrobial Resistance in Staphylococcus aureus MRSA strains, there was no >4-fold increase in the MIC for XF-73 after 55 passages. In contrast, there was an increase in the MICs for retapamulin (from 0.25 μg/ml to 4 to 8 μg/ml), for mupirocin (from 0.12 μg/ml to 16 to 512 μg/ml), for fusidic acid (from 0.12 μg/ml to 256 μg/ml), and for vancomycin (from 1 μg/ml to 8 μg/ml in two of the four strains tested). Further investigations using S. aureus NRS384 (USA300) and daptomycin demonstrated a 64-fold increase in the MIC after 55 passages (from 0.5 μg/ml to 32 μg/ml) with a >4-fold increase in the MIC obtained after only five passages. Sequencing analysis of selected isolates confirmed previously reported point mutations associated with daptomycin resistance. No cross-resistance to XF-73 was observed with the daptomycin-resistant strains, suggesting that whereas the two drugs act on the bacterial cell membrane, their specific site of action differs. XF-73 thus represents the first in a new class of antibacterial drugs, which (unlike the comparator antibiotics) after 55 passages exhibited a ≤4-fold increase in MIC against the strains tested. Antibacterial drugs with a low propensity for inducing bacterial resistance are much needed for the prevention and treatment of multidrug-resistant bacteria both within and outside the hospital setting. PMID:21149626

Prevalence of methicillin-resistant Staphylococcus aureus colonization in horses in Saskatchewan, Alberta, and British Columbia

PubMed Central

Tokateloff, Nathalie; Manning, Stephen T.; Weese, J. Scott; Campbell, John; Rothenburger, Jamie; Stephen, Craig; Bastura, Vanessa; Gow, Sheryl P.; Reid-Smith, Richard

2009-01-01

This study estimated the prevalence of methicillin resistant Staphylococcus aureus (MRSA) in nasal swabs of 458 horses in western Canada. The rate of colonization was 1.3% ± 5.84% [95% confidence interval (CI)], a rate similar to those reported elsewhere. Colonization tended to be transient and seemed unrelated to stress or administration of antimicrobials. Five of the 6 isolates were Canadian epidemic MRSA-5, a human clone that appears to predominate in horses in North America. The other isolate was spa type 539 (t034), a sequence type 398 strain, and this is the first report of this clone in horses in North America. Surveillance is warranted because of the potential of MRSA to cause disease in horses and humans. PMID:20119542

Effects of national antibiotic stewardship and infection control strategies on hospital-associated and community-associated meticillin-resistant Staphylococcus aureus infections across a region of Scotland: a non-linear time-series study.

PubMed

Lawes, Timothy; Lopez-Lozano, José-María; Nebot, Cesar A; Macartney, Gillian; Subbarao-Sharma, Rashmi; Dare, Ceri Rj; Wares, Karen D; Gould, Ian M

2015-12-01

Restriction of antibiotic consumption to below predefined total use thresholds might remove the selection pressure that maintains antimicrobial resistance within populations. We assessed the effect of national antibiotic stewardship and infection prevention and control programmes on prevalence density of meticillin-resistant Staphylococcus aureus (MRSA) infections across a region of Scotland. This non-linear time-series analysis and quasi-experimental study explored ecological determinants of MRSA epidemiology among 1,289,929 hospital admissions and 455,508 adults registered in primary care in northeast Scotland. Interventions included antibiotic stewardship to restrict use of so-called 4C (cephalosporins, co-amoxiclav, clindamycin, and fluoroquinolones) and macrolide antibiotics; a hand hygiene campaign; hospital environment inspections; and MRSA admission screening. Total effects were defined as the difference between scenarios with intervention (observed) and without intervention (predicted from time-series models). The primary outcomes were prevalence density of MRSA infections per 1000 occupied bed days (OBDs) in hospitals or per 10,000 inhabitants per day (IDs) in the community. During antibiotic stewardship, use of 4C and macrolide antibiotics fell by 47% (mean decrease 224 defined daily doses [DDDs] per 1000 OBDs, 95% CI 154-305, p=0·008) in hospitals and 27% (mean decrease 2·52 DDDs per 1000 IDs, 0·65-4·55, p=0·031) in the community. Hospital prevalence densities of MRSA were inversely related to intensified infection prevention and control, but positively associated with MRSA rates in neighbouring hospitals, importation pressures, bed occupancy, and use of fluoroquinolones, co-amoxiclav, and third-generation cephalosporins, or macrolide antibiotics that exceeded hospital-specific thresholds. Community prevalence density was predicted by hospital MRSA rates and above-threshold use of macrolides, fluoroquinolones, and clindamycin. MRSA prevalence

HLA molecules and nasal carriage of Staphylococcus aureus isolated from dialysis and kidney transplant patients at a hospital in Southern Brazil

PubMed Central

2012-01-01

Background Healthy individuals can host Staphylococcus aureus in the nasopharynx, body surface and vagina. Most invasive infections by this bacterium are endogenous, caused by strains spread from the nasopharynx of carriers. S. aureus is a pathogen involved in the etiology of hospital- and community-acquired infections. Transplant and dialysis patients are at risk of colonization or infection by multi-resistant S. aureus. Infection is directly linked to individual immunity, and the major histocompatibility complex (MHC) plays a crucial role in determining susceptibility to diseases. Different MHC specificities have been shown to be more frequent in individuals suffering from certain diseases. This study aimed to investigate the association between HLA class I (HLA-A and -B) and class II (HLA-DRB1) molecules and nasal carriage of S. aureus in dialysis and kidney transplant patients at a hospital in Southern Brazil. Results The sample consisted of 70 dialysis and 46 kidney transplant patients, totaling 116 patients. All subjects were typed for HLA molecules using LABType® SSO (One Lambda). Nasal swab samples of S. aureus were isolated from the nasal cavity (both nostrils) of patients undergoing dialysis or kidney transplantation. In renal dialysis patients, HLA-A*02 was the most frequent allele in both carriers (25.5%) and non-carriers (21.2%) of S. aureus. Allele A*68 was not observed in the carrier group, but the allele was observed six times in the non-carrier group (p = 0.0097). Regarding HLA-B and HLA-DRB1, no allele was shown to be involved in protection against or susceptibility to carriage of S. aureus. In kidney transplant patients, allele A*03 was more frequent in the non-carrier (20.83%) than in the carrier (5.88%) group (p = 0.0486). HLA-B*15 was present in carriers (5.88%) and non-carriers (25%) (p = 0.0179). Regarding class II alleles, DRB1*03 appeared to be related to susceptibility to carriage of S. aureus (p = 0.0319). Conclusions Our findings

Comparison of automated processing of flocked swabs with manual processing of fiber swabs for detection of nasal carriage of Staphylococcus aureus.

PubMed

Jones, Gillian; Matthews, Roger; Cunningham, Richard; Jenks, Peter

2011-07-01

The sensitivity of automated culture of Staphylococcus aureus from flocked swabs versus that of manual culture of fiber swabs was prospectively compared using nasal swabs from 867 patients. Automated culture from flocked swabs significantly increased the detection rate, by 13.1% for direct culture and 10.2% for enrichment culture.

Isolation of methicillin-resistant Staphylococcus spp. from ready-to-eat fish products.

PubMed

Sergelidis, D; Abrahim, A; Papadopoulos, T; Soultos, N; Martziou, E; Koulourida, V; Govaris, A; Pexara, A; Zdragas, A; Papa, A

2014-11-01

A hundred samples from ready-to-eat (RTE) fish products were examined for the presence and antimicrobial susceptibility of Staphylococcus spp. Staphylococci were isolated from 43% of these samples (n = 100). The identified species in the samples were Staphylococcus aureus (7%), Staphylococcus epidermidis (13%), Staphylococcus xylosus (12%), Staphylococcus sciuri (4%), Staphylococcus warneri (3%), Staphylococcus saprophyticus (2%), Staphylococcus schleiferi (1%) and Staphylococcus auricularis (1%). Two Staph. aureus (MRSA) isolates, three Staph. epidermidis (MRSE), five Staph. xylosus, four Staph. sciuri, one Staph. schleiferi and one Staph. saprophyticus isolates were resistant to oxacillin and all of them carried the mecA gene. The two MRSA isolates belonged to the spa types t316 (ST359) and t548 (ST5) and none of them was able to produce enterotoxins. Pulsed field gel electrophoresis for Staph. aureus and Staph. epidermidis isolates revealed 6 and 11 distinct PFGE types, respectively, reflecting diversity. The presence of methicillin-resistant staphylococci, especially MRSA and MRSE, in RTE fish products may constitute a potential health risk for consumers. This study provides the first data on the occurrence of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci in salted and smoked fish products in Greece. These results are important and useful for Staphylococcus spp. risk assessment and management programmes for ready-to-eat fish products. © 2014 The Society for Applied Microbiology.

High Prevalence of Mupirocin Resistance in Staphylococcus aureus Isolates from a Pediatric Population

PubMed Central

Antonov, Nina K.; Garzon, Maria C.; Morel, Kimberly D.; Whittier, Susan; Lauren, Christine T.

2015-01-01

Topical mupirocin is used widely to treat skin and soft tissue infections and to eradicate nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA). Few studies to date have characterized the rates of S. aureus mupirocin resistance in pediatric populations. We retrospectively studied 358 unique S. aureus isolates obtained from 249 children seen in a predominantly outpatient setting by the Division of Pediatric Dermatology at a major academic center in New York City between 1 May 2012 and 17 September 2013. Mupirocin resistance rates and the associated risk factors were determined using a logistic regression analysis. In our patient population, 19.3% of patients had mupirocin-resistant S. aureus isolates at the time of their first culture, and 22.1% of patients with S. aureus infection had a mupirocin-resistant isolate at some time during the study period. Overall, 31.3% of all S. aureus isolates collected during the study period were resistant to mupirocin. Prior mupirocin use was strongly correlated (odds ratio [OR] = 26.5; P = <0.001) with mupirocin resistance. Additional risk factors for mupirocin resistance included methicillin resistance, atopic dermatitis (AD), epidermolysis bullosa (EB), immunosuppression, and residence in northern Manhattan and the Bronx. Resistance to mupirocin is widespread in children with dermatologic complaints in the New York City area, and given the strong association with mupirocin exposure, it is likely that mupirocin use contributes to the increased resistance. Routine mupirocin testing may be important for MRSA decolonization strategies or the treatment of minor skin infections in children. PMID:25824213

Methicillin-resistant Staphylococcus aureus in hospitalized patients from the Bolivian Chaco.

PubMed

Bartoloni, Alessandro; Riccobono, Eleonora; Magnelli, Donata; Villagran, Ana Liz; Di Maggio, Tiziana; Mantella, Antonia; Sennati, Samanta; Revollo, Carmen; Strohmeyer, Marianne; Giani, Tommaso; Pallecchi, Lucia; Rossolini, Gian Maria

2015-01-01

Information is lacking on the methicillin-resistant Staphylococcus aureus (MRSA) clonal lineages circulating in Bolivia. We investigated the prevalence and molecular epidemiology of S. aureus colonization in hospitalized patients from the Bolivian Chaco, and compared their features with those of the few clinical isolates available from that setting. S. aureus nasal/inguinal colonization was investigated in 280 inpatients from eight hospitals in two point prevalence surveys (2012, n=90; 2013, n=190). Molecular characterization included genotyping (spa typing, multilocus sequence typing, and pulsed-field gel electrophoresis), detection of virulence genes, and SCCmec typing. Forty-one inpatients (14.6%) were S. aureus nasal/inguinal carriers, of whom five were colonized by MRSA (1.8%). MRSA isolates mostly belonged to spa-type t701, harboured SCCmec IVc, and were negative for Panton-Valentine leukocidin (PVL) genes. However, a USA300-related isolate was also detected, which showed the characteristics of the USA300 Latin American variant (USA300-LV; i.e., ST8, spa-type t008, SCCmec IVc, presence of PVL genes, absence of arcA). Notably, all the available MRSA clinical isolates (n=5, collected during 2011-2013) were also identified as USA300-LV. Overall, MRSA colonization in inpatients from the Bolivian Chaco was low. However, USA300-LV-related isolates were detected in colonization and infections, emphasizing the importance of implementing control measures to limit their further dissemination in this resource-limited area. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

PubMed

Wang, Li Jun; Du, Xiao Qin; Nyirimigabo, Eric; Shou, Song Tao

2014-04-01

It is rare to see a concurrent infection with infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus in Tianjin, China. Until now, there is still no any single recorded case of concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Variability of cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant bacteria in two Brazilian intensive care units.

PubMed

Damaceno, Quésia; Nicoli, Jacques R; Oliveira, Adriana

2015-01-01

To compare cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant organisms in two intensive care units. A prospective cohort study was performed in adult intensive care units of two hospitals in Belo Horizonte, Brazil (April 2012 to February 2013). Clinical and demographic data were first collected by reviewing patients' charts. Then, samples collected with nasal, groin, and perineum swabs were cultivated in selective media for 48 h at 37°C. After isolation, determination of antimicrobial susceptibility and biochemical identification were performed. A total of 53 cases of colonization were observed by the following bacteria in decreasing frequencies: imipenem-resistant Acinetobacter baumannii (50.9%), vancomycin-resistant Enterococcus faecalis (43.4%), extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (37.7%), imipenem-resistant Pseudomonas aeruginosa (32.1%), oxacillin-resistant Staphylococcus aureus (7.5%), and imipenem-resistant Klebsiella pneumoniae (5.7%). Among these colonization cases, 26 (49.0%) were followed by infection with bacteria phenotypically similar to those of the colonization. A relation between high population levels of colonization by most of the multidrug-resistant organisms at anatomical sites and a subsequent infection was observed. After colonization/infection, bacterial population levels decreased progressively and spontaneously until disappearance by day 45 in all the anatomical sites and for all the multidrug-resistant organisms. There was a correlation between high population levels of colonization by multidrug-resistant organisms at anatomical sites and a subsequent infection. Reduction in multidrug-resistant organism populations after colonization at anatomical sites could be a preventive measure to reduce evolution to infection as well as transmission of these bacteria between patients in intensive care unit.

Does rapid maxillary expansion increase nasopharyngeal space and improve nasal airway resistance?

PubMed

Langer, Marjorie Regina Eguren; Itikawa, Carla Enoki; Valera, Fabiana Cardoso Pereira; Matsumoto, Mírian Aiko Nakane; Anselmo-Lima, Wilma Terezinha

2011-01-01

To evaluate the effect of rapid maxillary expansion (RME) on the dimension of the nasopharyngeal space and its relation to nasal airway resistance. Twenty-five school-age children (from 7 to 10 year-old) with mouth and/or mixed breathing, with mixed dentition and uni- or bilateral posterior crossbite involving the deciduous canines and the first permanent molars, were evaluated. RME was placed and remained during 90 days. Rhinomanometry and orthodontic documentation were performed at four different times, i.e., before (T(1)), immediately after (T(2)), 90 days (T(3)) and 30 months (T(4)) after RME. Differences in nasopharyngeal area and in nasal airway resistance were observed only 30 months after RME, and could be explained by facial growth, and not because of the orthodontic procedure. RME does not influence on nasopharyngeal area or nasal airway resistance in long-term evaluation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Measuring the effect of enhanced cleaning in a UK hospital: a prospective cross-over study

PubMed Central

Dancer, Stephanie J; White, Liza F; Lamb, Jim; Girvan, E Kirsty; Robertson, Chris

2009-01-01

Background Increasing hospital-acquired infections have generated much attention over the last decade. There is evidence that hygienic cleaning has a role in the control of hospital-acquired infections. This study aimed to evaluate the potential impact of one additional cleaner by using microbiological standards based on aerobic colony counts and the presence of Staphylococcus aureus including meticillin-resistant S. aureus. Methods We introduced an additional cleaner into two matched wards from Monday to Friday, with each ward receiving enhanced cleaning for six months in a cross-over design. Ten hand-touch sites on both wards were screened weekly using standardised methods and patients were monitored for meticillin-resistant S. aureus infection throughout the year-long study. Patient and environmental meticillin-resistant S. aureus isolates were characterised using molecular methods in order to investigate temporal and clonal relationships. Results Enhanced cleaning was associated with a 32.5% reduction in levels of microbial contamination at hand-touch sites when wards received enhanced cleaning (P < 0.0001: 95% CI 20.2%, 42.9%). Near-patient sites (lockers, overbed tables and beds) were more frequently contaminated with meticillin-resistant S. aureus/S. aureus than sites further from the patient (P = 0.065). Genotyping identified indistinguishable strains from both hand-touch sites and patients. There was a 26.6% reduction in new meticillin-resistant S. aureus infections on the wards receiving extra cleaning, despite higher meticillin-resistant S. aureus patient-days and bed occupancy rates during enhanced cleaning periods (P = 0.032: 95% CI 7.7%, 92.3%). Adjusting for meticillin-resistant S. aureus patient-days and based upon nine new meticillin-resistant S. aureus infections seen during routine cleaning, we expected 13 new infections during enhanced cleaning periods rather than the four that actually occurred. Clusters of new meticillin-resistant S. aureus

Measuring the effect of enhanced cleaning in a UK hospital: a prospective cross-over study.

PubMed

Dancer, Stephanie J; White, Liza F; Lamb, Jim; Girvan, E Kirsty; Robertson, Chris

2009-06-08

Increasing hospital-acquired infections have generated much attention over the last decade. There is evidence that hygienic cleaning has a role in the control of hospital-acquired infections. This study aimed to evaluate the potential impact of one additional cleaner by using microbiological standards based on aerobic colony counts and the presence of Staphylococcus aureus including meticillin-resistant S. aureus. We introduced an additional cleaner into two matched wards from Monday to Friday, with each ward receiving enhanced cleaning for six months in a cross-over design. Ten hand-touch sites on both wards were screened weekly using standardised methods and patients were monitored for meticillin-resistant S. aureus infection throughout the year-long study. Patient and environmental meticillin-resistant S. aureus isolates were characterised using molecular methods in order to investigate temporal and clonal relationships. Enhanced cleaning was associated with a 32.5% reduction in levels of microbial contamination at hand-touch sites when wards received enhanced cleaning (P < 0.0001: 95% CI 20.2%, 42.9%). Near-patient sites (lockers, overbed tables and beds) were more frequently contaminated with meticillin-resistant S. aureus/S. aureus than sites further from the patient (P = 0.065). Genotyping identified indistinguishable strains from both hand-touch sites and patients. There was a 26.6% reduction in new meticillin-resistant S. aureus infections on the wards receiving extra cleaning, despite higher meticillin-resistant S. aureus patient-days and bed occupancy rates during enhanced cleaning periods (P = 0.032: 95% CI 7.7%, 92.3%). Adjusting for meticillin-resistant S. aureus patient-days and based upon nine new meticillin-resistant S. aureus infections seen during routine cleaning, we expected 13 new infections during enhanced cleaning periods rather than the four that actually occurred. Clusters of new meticillin-resistant S. aureus infections were identified 2

Evaluation of an autoclave resistant anatomic nose model for the testing of nasal swabs

PubMed Central

Bartolitius, Lennart; Warnke, Philipp; Ottl, Peter; Podbielski, Andreas

2014-01-01

A nose model that allows for the comparison of different modes of sample acquisition as well as of nasal swab systems concerning their suitability to detect defined quantities of intranasal microorganisms, and further for training procedures of medical staff, was evaluated. Based on an imprint of a human nose, a model made of a silicone elastomer was formed. Autoclave stability was assessed. Using an inoculation suspension containing Staphylococcus aureus and Staphylococcus epidermidis, the model was compared with standardized glass plate inoculations. Effects of inoculation time, mode of sampling, and sample storage time were assessed. The model was stable to 20 autoclaving cycles. There were no differences regarding the optimum coverage from the nose and from glass plates. Optimum sampling time was 1 h after inoculation. Storage time after sampling was of minor relevance for the recovery. Rotating the swab around its own axis while circling the nasal cavity resulted in best sampling results. The suitability of the assessed nose model for the comparison of sampling strategies and systems was confirmed. Without disadvantages in comparison with sampling from standardized glass plates, the model allows for the assessment of a correct sampling technique due to its anatomically correct shape. PMID:25215192

Evaluation of an autoclave resistant anatomic nose model for the testing of nasal swabs.

PubMed

Bartolitius, Lennart; Frickmann, Hagen; Warnke, Philipp; Ottl, Peter; Podbielski, Andreas

2014-09-01

A nose model that allows for the comparison of different modes of sample acquisition as well as of nasal swab systems concerning their suitability to detect defined quantities of intranasal microorganisms, and further for training procedures of medical staff, was evaluated. Based on an imprint of a human nose, a model made of a silicone elastomer was formed. Autoclave stability was assessed. Using an inoculation suspension containing Staphylococcus aureus and Staphylococcus epidermidis, the model was compared with standardized glass plate inoculations. Effects of inoculation time, mode of sampling, and sample storage time were assessed. The model was stable to 20 autoclaving cycles. There were no differences regarding the optimum coverage from the nose and from glass plates. Optimum sampling time was 1 h after inoculation. Storage time after sampling was of minor relevance for the recovery. Rotating the swab around its own axis while circling the nasal cavity resulted in best sampling results. The suitability of the assessed nose model for the comparison of sampling strategies and systems was confirmed. Without disadvantages in comparison with sampling from standardized glass plates, the model allows for the assessment of a correct sampling technique due to its anatomically correct shape.

Comparison of Automated Processing of Flocked Swabs with Manual Processing of Fiber Swabs for Detection of Nasal Carriage of Staphylococcus aureus▿‡

PubMed Central

Jones, Gillian; Matthews, Roger; Cunningham, Richard; Jenks, Peter

2011-01-01

The sensitivity of automated culture of Staphylococcus aureus from flocked swabs versus that of manual culture of fiber swabs was prospectively compared using nasal swabs from 867 patients. Automated culture from flocked swabs significantly increased the detection rate, by 13.1% for direct culture and 10.2% for enrichment culture. PMID:21525218

Characterization of resistance to selected antibiotics and Panton-Valentine leukocidin-positive Staphylococcus aureus in a healthy student population at a Malaysian University

PubMed Central

Suhaili, Zarizal; Rafee, Putri ’Amira; Mat Azis, Norhidayah; Yeo, Chew Chieng; Nordin, Syafinaz Amin; Abdul Rahim, Abdul Rachman; Al-Obaidi, Mazen M. Jamil; Mohd Desa, Mohd Nasir

2018-01-01

Abstract Introduction This study aims to assess the antimicrobial susceptibility profiles of Staphylococcus aureus strains isolated from university students and to determine the prevalence of constitutive and inducible clindamycin resistance, the latter being able to cause therapeutic failure due to false in vitro clindamycin susceptibility. Methods S. aureus strains were isolated from the nasal swabs of 200 health sciences students of a Malaysian university. Twelve classes of antibiotics were used to evaluate the antimicrobial susceptibility profiles with the macrolide-lincosamide-streptogramin B (MLSB) phenotype for inducible clindamycin resistance determined by the double-diffusion test (D-test). Carriage of resistance and virulence genes was performed by PCR on S. aureus isolates that were methicillin resistant, erythromycin resistant and/or positive for the leukocidin gene, pvl (n=15). Results Forty-nine isolates were viable and identified as S. aureus with four of the isolates characterized as methicillin-resistant S. aureus (MRSA; 2.0%). All isolates were susceptible to the antibiotics tested except for penicillin (resistance rate of 49%), erythromycin (16%), oxacillin (8%), cefoxitin (8%) and clindamycin (4%). Of the eight erythromycin-resistant isolates, iMLSB was identified in five isolates (three of which were also MRSA). The majority of the erythromycin-resistant isolates harbored the msrA gene (four iMLSB) with the remaining iMLSB isolate harboring the ermC gene. Conclusion The presence of MRSA isolates which are also iMLSB in healthy individuals suggests that nasal carriage may play a role as a potential reservoir for the transmission of these pathogens. PMID:29564245

Characterization of resistance to selected antibiotics and Panton-Valentine leukocidin-positive Staphylococcus aureus in a healthy student population at a Malaysian University.

PubMed

Suhaili, Zarizal; Rafee, Putri 'Amira; Mat Azis, Norhidayah; Yeo, Chew Chieng; Nordin, Syafinaz Amin; Abdul Rahim, Abdul Rachman; Al-Obaidi, Mazen M Jamil; Mohd Desa, Mohd Nasir

2018-03-01

This study aims to assess the antimicrobial susceptibility profiles of Staphylococcus aureus strains isolated from university students and to determine the prevalence of constitutive and inducible clindamycin resistance, the latter being able to cause therapeutic failure due to false in vitro clindamycin susceptibility. S. aureus strains were isolated from the nasal swabs of 200 health sciences students of a Malaysian university. Twelve classes of antibiotics were used to evaluate the antimicrobial susceptibility profiles with the macrolide-lincosamide-streptogramin B (MLS B ) phenotype for inducible clindamycin resistance determined by the double-diffusion test (D-test). Carriage of resistance and virulence genes was performed by PCR on S. aureus isolates that were methicillin resistant, erythromycin resistant and/or positive for the leukocidin gene, pvl (n=15). Forty-nine isolates were viable and identified as S. aureus with four of the isolates characterized as methicillin-resistant S. aureus (MRSA; 2.0%). All isolates were susceptible to the antibiotics tested except for penicillin (resistance rate of 49%), erythromycin (16%), oxacillin (8%), cefoxitin (8%) and clindamycin (4%). Of the eight erythromycin-resistant isolates, iMLS B was identified in five isolates (three of which were also MRSA). The majority of the erythromycin-resistant isolates harbored the msrA gene (four iMLS B ) with the remaining iMLS B isolate harboring the ermC gene. The presence of MRSA isolates which are also iMLS B in healthy individuals suggests that nasal carriage may play a role as a potential reservoir for the transmission of these pathogens.

Multiplex PCR assay to identify methicillin-resistant Staphylococcus haemolyticus.

PubMed

Schuenck, Ricardo P; Pereira, Eliezer M; Iorio, Natalia L P; Dos Santos, Kátia R N

2008-04-01

Staphylococcus haemolyticus is the most frequently coagulase-negative Staphylococcus species associated with antimicrobial resistance isolated from nosocomial infections. We developed an accurate and simple multiplex PCR assay to identify methicillin-resistant S. haemolyticus (MRSH) isolates. We designed species-specific primers of the mvaA gene that encodes a 3-hydroxy-3-methylglutaryl coenzyme A involved in the mevalonate pathway of the microorganism. Simultaneously, mecA gene primers of methicillin resistance were also used. The PCR assay was established using 16 strains of different reference Staphylococcus species and validated with a collection of 147 clinical staphylococcal isolates that were also phenotypically characterized. Reliable results for the detection of MRSH isolates were obtained for 100% of the strains evaluated, showing that this PCR assay can be used for the routine microbiology laboratories. This is the first report using species-specific multiplex PCR to detect a single segment of S. haemolyticus associated with a segment of mecA gene.

Rapid environmental contamination of a new nursing home with antimicrobial-resistant organisms preceding occupation by residents.

PubMed

Ludden, C; Cormican, M; Austin, B; Morris, D

2013-04-01

Nursing homes are reservoirs for antimicrobial-resistant organisms (AROs). This study examined the time to environmental contamination with AROs in a new-build nursing home. Environmental sites in an occupied nursing home (N = 18) and a newly built replacement nursing home (N = 21) were monitored during an 11-week period before and after residents transferred between buildings. Meticillin-resistant Staphylococcus aureus was detected during commissioning in the new building and was a frequent finding throughout the building after residents had moved in. Extended-spectrum beta-lactamase-producing E. coli O25b:ST131 was detected once. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Contamination of X-ray Cassettes with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus haemolyticus in a Radiology Department

PubMed Central

Kim, Han-Sung; Park, Ji-Young; Koo, Hyun-Sook; Choi, Chul-Sun; Song, Wonkeun; Cho, Hyoun Chan; Lee, Kyu Man

2012-01-01

Background We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). Methods The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 µg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. Results Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. Conclusions X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci. PMID:22563556

Contamination of X-ray cassettes with methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus haemolyticus in a radiology department.

PubMed

Kim, Jae-Seok; Kim, Han-Sung; Park, Ji-Young; Koo, Hyun-Sook; Choi, Chul-Sun; Song, Wonkeun; Cho, Hyoun Chan; Lee, Kyu Man

2012-05-01

We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 µg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci.

The Evaluation of Methicillin Resistance in Staphylococcus aboard the International Space Station

NASA Technical Reports Server (NTRS)

Ott, C. M.; Bassinger, V. J.; Fontenot, S. L.; Castro, V. A.; Pierson, D. L.

2005-01-01

The International Space Station (ISS) represents a semi-closed environment with a high level of crewmember interaction. As community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a health concern in environments with susceptible hosts in close proximity, an evaluation of isolates of clinical and environmental Staphylococcus aureus and coagulase negative Staphylococcus was performed to determine if this trend was also present in astronauts aboard ISS or the space station itself. Rep-PCR fingerprinting analysis of archived ISS isolates confirmed our earlier studies indicating a transfer of S. aureus between crewmembers. In addition, this fingerprinting also indicated a transfer between crewmembers and their environment. While a variety of S. aureus were identified from both the crewmembers and the environment, phenotypic evaluations indicated minimal methicillin resistance. However, positive results for the Penicillin Binding Protein, indicative of the presence of the mecA gene, were detected in multiple isolates of archived Staphylococcus epidermidis and Staphylococcus haemolyticus. Phenotypic analysis of these isolates confirmed their resistance to methicillin. While MRSA has not been isolated aboard ISS, the potential exists for the transfer of the gene, mecA, from coagulase negative environmental Staphylococcus to S. aureus creating MRSA strains. This study suggests the need to expand environmental monitoring aboard long duration exploration spacecraft to include antibiotic resistance profiling.

Antimicrobial resistance of Staphylococcus species isolated from Lebanese dairy-based products.

PubMed

Zouhairi, O; Saleh, I; Alwan, N; Toufeili, I; Barbour, E; Harakeh, S

2012-12-04

The study evaluated the antimicrobial resistance of molecularly characterized strains of Staphylococcus aureus and S. saprophyticus isolated from 3 Lebanese dairy-based food products that are sometimes consumed raw: kishk, shanklish and baladi cheese. Suspected Staphylococcus isolates were identified initially using standard biochemical tests, then strains that were confirmed by polymerase chain reaction (29 S. aureus and 17 S. saprophyticus) were evaluated for their susceptibility to different antimicrobials. The highest levels of contamination with staphylococci were in baladi cheese. Resistance rates ranged from 67% to gentamicin to 94% to oxacillin and clindamycin. The results suggest that these locally made dairy-based foods may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus spp.

Methicillin-resistant Staphylococcus sp. colonizing health care workers of a cancer hospital

PubMed Central

Costa, Dayane de Melo; Kipnis, André; Leão-Vasconcelos, Lara Stefânia Netto de Oliveira; Rocha-Vilefort, Larissa Oliveira; Telles, Sheila Araújo; André, Maria Cláudia Dantas Porfírio Borges; Tipple, Anaclara Ferreira Veiga; Lima, Ana Beatriz Mori; Ribeiro, Nádia Ferreira Gonçalves; Pereira, Mayara Regina; Prado-Palos, Marinésia Aparecida

2014-01-01

The aim of the study was to analyze epidemiological and microbiological aspects of oral colonization by methicillin-resistant Staphylococcus of health care workers in a cancer hospital. Interview and saliva sampling were performed with 149 health care workers. Antimicrobial resistance was determined by disk diffusion and minimum inhibitory concentration. Polymerase Chain Reaction, Internal Transcribed Spacer-Polymerase Chain Reaction and Pulsed Field Gel Electrophoresis were performed for genotypic characterization of methicillin-resistant Staphylococcus. Risk factors were determined by logistic regression. Methicillin-resistant Staphylococcus colonization prevalence was 19.5%, denture wearing (p = 0.03), habit of nail biting (p = 0.04) and preparation and administration of antimicrobial (p = 0.04) were risk factors identified. All methicillin-resistant Staphylococcus were S. epidermidis, 94.4% of them had mecA gene. Closely related and indistinguishable methicillin-resistant S. epidermidis were detected. These results highlight that HCWs which have contact with patient at high risk for developing infections were identified as colonized by MRSE in the oral cavity, reinforcing this cavity as a reservoir of these bacteria and the risk to themselves and patients safety, because these microorganisms may be spread by coughing and talking. PMID:25477910

Antimicrobial resistance of Staphylococcus aureus isolates from dairy cows and genetic diversity of resistant isolates

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results i...

Accurate Detection of Methicillin-Resistant Staphylococcus aureus in Mixtures by Use of Single-Bacterium Duplex Droplet Digital PCR.

PubMed

Luo, Jun; Li, Junhua; Yang, Hang; Yu, Junping; Wei, Hongping

2017-10-01

Accurate and rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is needed to screen MRSA carriers and improve treatment. The current widely used duplex PCR methods are not able to differentiate MRSA from coexisting methicillin-susceptible S. aureus (MSSA) or other methicillin-resistant staphylococci. In this study, we aimed to develop a direct method for accurate and rapid detection of MRSA in clinical samples from open environments, such as nasal swabs. The new molecular assay is based on detecting the cooccurrence of nuc and mecA markers in a single bacterial cell by utilizing droplet digital PCR (ddPCR) with the chimeric lysin ClyH for cell lysis. The method consists of (i) dispersion of an intact single bacterium into nanoliter droplets, (ii) temperature-controlled release of genomic DNA (gDNA) by ClyH at 37°C, and (iii) amplification and detection of the markers ( nuc and mecA ) using standard TaqMan chemistries with ddPCR. Results were analyzed based on MRSA index ratios used for indicating the presence of the duplex-positive markers in droplets. The method was able to achieve an absolute limit of detection (LOD) of 2,900 CFU/ml for MRSA in nasal swabs spiked with excess amounts of Escherichia coli , MSSA, and other mecA -positive bacteria within 4 h. Initial testing of 104 nasal swabs showed that the method had 100% agreement with the standard culture method, while the normal duplex qPCR method had only about 87.5% agreement. The single-bacterium duplex ddPCR assay is rapid and powerful for more accurate detection of MRSA directly from clinical specimens. Copyright © 2017 American Society for Microbiology.

Accurate Detection of Methicillin-Resistant Staphylococcus aureus in Mixtures by Use of Single-Bacterium Duplex Droplet Digital PCR

PubMed Central

Luo, Jun; Li, Junhua; Yang, Hang; Yu, Junping

2017-01-01

ABSTRACT Accurate and rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is needed to screen MRSA carriers and improve treatment. The current widely used duplex PCR methods are not able to differentiate MRSA from coexisting methicillin-susceptible S. aureus (MSSA) or other methicillin-resistant staphylococci. In this study, we aimed to develop a direct method for accurate and rapid detection of MRSA in clinical samples from open environments, such as nasal swabs. The new molecular assay is based on detecting the cooccurrence of nuc and mecA markers in a single bacterial cell by utilizing droplet digital PCR (ddPCR) with the chimeric lysin ClyH for cell lysis. The method consists of (i) dispersion of an intact single bacterium into nanoliter droplets, (ii) temperature-controlled release of genomic DNA (gDNA) by ClyH at 37°C, and (iii) amplification and detection of the markers (nuc and mecA) using standard TaqMan chemistries with ddPCR. Results were analyzed based on MRSA index ratios used for indicating the presence of the duplex-positive markers in droplets. The method was able to achieve an absolute limit of detection (LOD) of 2,900 CFU/ml for MRSA in nasal swabs spiked with excess amounts of Escherichia coli, MSSA, and other mecA-positive bacteria within 4 h. Initial testing of 104 nasal swabs showed that the method had 100% agreement with the standard culture method, while the normal duplex qPCR method had only about 87.5% agreement. The single-bacterium duplex ddPCR assay is rapid and powerful for more accurate detection of MRSA directly from clinical specimens. PMID:28724560

Antimicrobial Stewardship Lessons From Mupirocin Use and Resistance in Methicillin-Resitant Staphylococcus Aureus.

PubMed

Peterson, Lance R; Samia, Noelle I; Skinner, Andrew M; Chopra, Amit; Smith, Becky

2017-01-01

The quantitative relationship between antimicrobial agent consumption and rise or fall of antibiotic resistance has rarely been studied. We began all admission surveillance testing for methicillin-resistant Staphylococcus aureus (MRSA) in August 2005 with subsequent contact isolation and decolonization using nasally applied mupirocin ointment for those colonized. In October 2012, we discontinued decolonization of medical (nonsurgical service) patients. We conducted a retrospective study from 2007 through 2014 of 445680 patients; 35235 were assessed because of mupirocin therapy and positive test results for MRSA. We collected data on those patients receiving 2% mupirocin ointment for decolonization to determine the defined daily doses (DDDs). A nonparametric regression technique was used to quantitate the effect of mupirocin consumption on drug resistance in MRSA. Using regressive modeling, we found that, when consumption was consistently >25 DDD/1000 patient-days, there was a statistically significant increase in mupirocin resistance with a correlating positive rate of change. When consumption was ≤25 DDD/1000 patient-days, there was a statistically significant decrease in mupirocin resistance with a correlating negative rate of change. The scatter plot of fitted versus observed mupirocin resistance values showed an R 2 value of 0.89-a high correlation between mupirocin use and resistance. Use of the antimicrobial agent mupirocin for decolonization had a threshold of approximately 25 DDD/1000 patient-days that separated a rise and fall of resistance within the acute-care setting. This has implications for how widely mupirocin can be used for decolonization, as well as for setting consumption thresholds when prescribing antimicrobials as part of stewardship programs. © The Author 2017. Published by Oxford University Press on behalf of Infectious Diseases Society of America.

Quality Control of Direct Molecular Diagnostics for Methicillin-Resistant Staphylococcus aureus▿

PubMed Central

van Belkum, Alex; Niesters, Hubert G. M.; MacKay, William G.; van Leeuwen, Willem B.

2007-01-01

Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing 102 to 103 MRSA cells were frequently reported to be negative. MRSE samples were scored as negative by all commercial tests but by only two out of three in-house tests. PMID:17581936

Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus: methicillin-resistant isolates are detected directly in blood cultures by multiplex PCR.

PubMed

Pereira, Eliezer M; Schuenck, Ricardo P; Malvar, Karoline L; Iorio, Natalia L P; Matos, Pricilla D M; Olendzki, André N; Oelemann, Walter M R; dos Santos, Kátia R N

2010-03-31

In this study, we standardized and evaluated a multiplex-PCR methodology using specific primers to identify Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus and their methicillin-resistance directly from blood cultures. Staphylococci clinical isolates (149) and control strains (16) previously identified by conventional methods were used to establish the multiplex PCR protocol. Subsequently, this methodology was evaluated using a fast and cheap DNA extraction protocol from 25 staphylococci positive blood cultures. A wash step of the pellet with 0.1% bovine serum albumin (BSA) solution was performed to reduce PCR inhibitors. Amplicons of 154bp (mecA gene), 271bp (S. haemolyticus mvaA gene) and 108 and 124bp (S. aureus and S. epidermidis species-specific fragments, respectively) were observed. Reliable results were obtained for 100% of the evaluated strains, suggesting that this new multiplex-PCR combined with an appropriate DNA-extraction method could be useful in the laboratory for fast and accurate identification of three staphylococci species and simultaneously their methicillin resistance directly in blood cultures.

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

PubMed

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region.

PubMed

Schinasi, Leah; Wing, Steve; Augustino, Kerri L; Ramsey, Keith M; Nobles, Delores L; Richardson, David B; Price, Lance B; Aziz, Maliha; MacDonald, Pia D M; Stewart, Jill R

2014-06-23

Distinct strains of methicillin resistant Staphylococcus aureus (MRSA) have been identified on livestock and livestock workers. Industrial food animal production may be an important environmental reservoir for human carriage of these pathogenic bacteria. The objective of this study was to investigate environmental and occupational exposures associated with nasal carriage of MRSA in patients hospitalized at Vidant Medical Center, a tertiary hospital serving a region with intensive livestock production in eastern North Carolina. MRSA nasal carriage was identified via nasal swabs collected within 24 hours of hospital admission. MRSA carriers (cases) were gender and age matched to non-carriers (controls). Participants were interviewed about recent environmental and occupational exposures. Home addresses were geocoded and publicly available data were used to estimate the density of swine in residential census block groups of residence. Conditional logistic regression models were used to derive odds ratio (OR) estimates and 95% confidence intervals (CI). Presence of the scn gene in MRSA isolates was assessed. In addition, multi locus sequence typing (MLST) of the MRSA isolates was performed, and the Diversilab® system was used to match the isolates to USA pulsed field gel electrophoresis types. From July - December 2011, 117 cases and 119 controls were enrolled. A higher proportion of controls than cases were current workforce members (41.2% vs. 31.6%) Cases had a higher odds of living in census block groups with medium densities of swine (OR: 4.76, 95% CI: 1.36-16.69) and of reporting the ability to smell odor from a farm with animals when they were home (OR: 1.51, 95% CI: 0.80-2.86). Of 49 culture positive MRSA isolates, all were scn positive. Twenty-two isolates belonged to clonal complex 5. Absence of livestock workers in this study precluded evaluation of occupational exposures. Higher odds of MRSA in medium swine density areas could reflect environmental exposure

A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region

PubMed Central

2014-01-01

Background Distinct strains of methicillin resistant Staphylococcus aureus (MRSA) have been identified on livestock and livestock workers. Industrial food animal production may be an important environmental reservoir for human carriage of these pathogenic bacteria. The objective of this study was to investigate environmental and occupational exposures associated with nasal carriage of MRSA in patients hospitalized at Vidant Medical Center, a tertiary hospital serving a region with intensive livestock production in eastern North Carolina. Methods MRSA nasal carriage was identified via nasal swabs collected within 24 hours of hospital admission. MRSA carriers (cases) were gender and age matched to non-carriers (controls). Participants were interviewed about recent environmental and occupational exposures. Home addresses were geocoded and publicly available data were used to estimate the density of swine in residential census block groups of residence. Conditional logistic regression models were used to derive odds ratio (OR) estimates and 95% confidence intervals (CI). Presence of the scn gene in MRSA isolates was assessed. In addition, multi locus sequence typing (MLST) of the MRSA isolates was performed, and the Diversilab® system was used to match the isolates to USA pulsed field gel electrophoresis types. Results From July - December 2011, 117 cases and 119 controls were enrolled. A higher proportion of controls than cases were current workforce members (41.2% vs. 31.6%) Cases had a higher odds of living in census block groups with medium densities of swine (OR: 4.76, 95% CI: 1.36-16.69) and of reporting the ability to smell odor from a farm with animals when they were home (OR: 1.51, 95% CI: 0.80-2.86). Of 49 culture positive MRSA isolates, all were scn positive. Twenty-two isolates belonged to clonal complex 5. Conclusions Absence of livestock workers in this study precluded evaluation of occupational exposures. Higher odds of MRSA in medium swine density

Nasal and conjunctival screening prior to refractive surgery: an observational and cross-sectional study

PubMed Central

Kitazawa, Koji; Sotozono, Chie; Sakamoto, Masako; Sasaki, Miho; Hieda, Osamu; Yamasaki, Toshihide; Kinoshita, Shigeru

2016-01-01

Objectives To investigate bacterial flora of clinically healthy conjunctiva and nasal cavity among patients prior to refractive surgery, as well as the characteristics of patients with methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Design Observational and cross-sectional study. Setting A single-centre study in Japan. Participants 120 consecutive patients pre-refractive surgery. Primary and secondary outcome measures methods Samples were obtained from the right conjunctival sac and the nasal cavity of 120 consecutive patients prior to refractive surgery and were then measured for the levels of the minimum inhibitory concentration (MIC) of antibiotics. Patients were interviewed regarding their occupation, family living situation and any personal history of atopic dermatitis, asthma, smoking or contact lens wear. Results Propionibacterium acnes (P. acnes) (32.5%) and Staphylococcus epidermidis (4.2%) were detected from the conjunctival sac. S. epidermidis was the most commonly isolated (68.3%) in the nasal cavity. Of the 30 patients (25.0%) with colonisation by S. aureus, 2 patients, both of whom were healthcare workers with atopic dermatitis, were found to be positive for MRSA in the nasal cavity. A history of contact lens wear, asthma or smoking, as well as patient gender and age, was not associated with MRSA colonisation. Conclusions There were only 2 patients who were colonised with MRSA, both of whom were healthcare workers with atopic dermatitis. P. acnes was predominantly found in the conjunctival sac. Further study is needed to investigate the involvement between nasal and conjunctival flora, and risk factors for infectious complications. PMID:27160843

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

PubMed

Enayet, Iram; Nazeri, Ali; Johnson, Leonard B; Riederer, Kathleen; Pawlak, Joan; Saravolatz, Louis D

2006-04-01

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Phenotypic and molecular characteristics of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in slaughterhouse pig-related workers and control workers in Guangdong Province, China.

PubMed

Wang, X L; Li, L; Li, S M; Huang, J Y; Fan, Y P; Yao, Z J; Ye, X H; Chen, S D

2017-07-01

Pig farmers and veterinarians have high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) due to the occupational livestock exposure, while few reported this association on slaughterhouse workers. We conducted this cross-sectional study to explore the phenotypic and molecular characteristics of S. aureus and MRSA in slaughterhouse pig-related workers and control workers in Guangdong Province, China. Participants were interviewed and provided two nasal swabs. Swabs were tested for S. aureus, and isolates were further tested for antimicrobial susceptibility, virulence genes and multi-locus sequence typing. Compared with control workers, pig-related workers have significantly higher prevalence of MRSA carriage (adjusted odd ratio (aOR) 3·70, 95% CI 1·63-8·40). The proportions of MRSA resistant to clindamycin, erythromycin, tetracycline or chloromycetin were significantly higher in pig-related workers than in control workers. The predominant phenotypes of S. aureus were resistant to penicillin, clindamycin, erythromycin and tetracycline. Three MRSA CC9 isolates with livestock-associated characteristics (resistance to tetracycline and absence of immune evasion cluster (IEC) genes) were detected in pig-related workers but not in control workers. For human-associated CCs (CC7, CC59, CC6, and CC188), there was no significant difference in IEC profile or antimicrobial resistance between the groups. These findings reveal that there may be a potential risk for livestock-to-human transmission of LA-MRSA and human-to-human transmission of human-associated MRSA.

A Nasal Epithelial Receptor for Staphylococcus aureus WTA Governs Adhesion to Epithelial Cells and Modulates Nasal Colonization

PubMed Central

Faulstich, Manuela; Grau, Timo; Severin, Yannik; Unger, Clemens; Hoffmann, Wolfgang H.; Rudel, Thomas; Autenrieth, Ingo B.; Weidenmaier, Christopher

2014-01-01

Nasal colonization is a major risk factor for S. aureus infections. The mechanisms responsible for colonization are still not well understood and involve several factors on the host and the bacterial side. One key factor is the cell wall teichoic acid (WTA) of S. aureus, which governs direct interactions with nasal epithelial surfaces. We report here the first receptor for the cell wall glycopolymer WTA on nasal epithelial cells. In several assay systems this type F-scavenger receptor, termed SREC-I, bound WTA in a charge dependent manner and mediated adhesion to nasal epithelial cells in vitro. The impact of WTA and SREC-I interaction on epithelial adhesion was especially pronounced under shear stress, which resembles the conditions found in the nasal cavity. Most importantly, we demonstrate here a key role of the WTA-receptor interaction in a cotton rat model of nasal colonization. When we inhibited WTA mediated adhesion with a SREC-I antibody, nasal colonization in the animal model was strongly reduced at the early onset of colonization. More importantly, colonization stayed low over an extended period of 6 days. Therefore we propose targeting of this glycopolymer-receptor interaction as a novel strategy to prevent or control S. aureus nasal colonization. PMID:24788600

Diversity of methicillin-resistant Staphylococcus aureus (MRSA) isolated from Austrian ruminants and New World camelids.

PubMed

Schauer, B; Krametter-Frötscher, R; Knauer, F; Ehricht, R; Monecke, S; Feßler, A T; Schwarz, S; Grunert, T; Spergser, J; Loncaric, I

2018-02-01

The aim of this study was to determine the prevalence, the antimicrobial resistance patterns and the genetic diversity of methicillin-resistant Staphylococcus aureus (MRSA) from Austrian ruminants and New World camelids that were treated at the University of Veterinary Medicine, Vienna. Between April 2014 and January 2017, 723 nasal swabs originating from ruminants and New World camelids were examined. MRSA isolates were characterized by mecA/mecA1/mecC PCRs and by DNA microarray analysis. They were genotyped by spa typing, dru typing, MLST and MLVA. Glycopolymer fingerprinting by FTIR spectroscopy was also performed. Antimicrobial susceptibility testing was conducted by agar disk diffusion. Twelve MRSA isolates were mecA-positive, whereas three were mecC-positive. The MRSA isolates carried five different SCCmec elements, and belonged to three sequence types (ST45, ST130, ST398). The MRSA isolates displayed seven different resistance phenotypes. The present study describes for the first time mecC-carrying MRSA isolates originating from domesticated animals in Austria. More systematic studies are needed to unravel the role of ruminants and New World camelids as reservoirs for MRSA as a potential risk for zooanthropogenic transmission. Copyright © 2018 Elsevier B.V. All rights reserved.

Identification of Staphylococcus epidermidis with transferrable mupirocin resistance from canine skin.

PubMed

Rossi, C C; Salgado, B A B; Barros, E M; de Campos Braga, P A; Eberlin, M N; Lilenbaum, W; Giambiagi-deMarval, M

2018-05-01

Resistance to mupirocin was analysed in Staphylococcus spp. isolated from healthy dogs (n=21) and dogs with pyoderma (n=47) or otitis externa (n=52). Isolates were identified to species level by MALDI-TOF and PCR-RFLP of the groEL gene. One isolate of Staphylococcus epidermidis from the skin of a healthy dog, which harboured a plasmid carrying the mupA gene, was resistant to mupirocin. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dalbavancin reduces biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE).

PubMed

Knafl, D; Tobudic, S; Cheng, S C; Bellamy, D R; Thalhammer, F

2017-04-01

Activity of dalbavancin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) in biofilm was investigated and the microbicidal biofilm concentrations (MBC) were determined. Biofilms obtained from ten MRSA and ten MRSE bloodstream isolates, collected from patients in the General Hospital of Vienna between 2012 and 2015, were incubated with dalbavancin in trypticase soy broth (TSB) in serial dilution from 0.0625 mg/l to 256 mg/l using a microtiter plate biofilm model. The plates were incubated for 24 h at 37 ° C and 50% humidity. Biofilms were fixed with 2.5% glutaraldehyde and stained with crystal violet. Subsequently the optical density (OD 620 ) was used to measure the MBC, defined as the concentration of dalbavancin leading to a 50% reduction of biofilm. MBC for MRSA was 1 mg/l-4 mg/l (minimal inhibitory concentrations (MIC) 0.0312 mg/l-0.064 mg/l). MBC for MRSE was 2 mg/l-16 mg/l (MIC 0.023 mg/l-0.0625 mg/l). Dalbavancin successfully reduced MRSA and MRSE in biofilms, and therefore provides a promising option for the treatment of biofilm-associated infections.

Antimicrobial resistance and virulence characterization of Staphylococcus aureus and coagulase-negative staphylococci from imported beef meat.

PubMed

Osman, Kamelia; Alvarez-Ordóñez, Avelino; Ruiz, Lorena; Badr, Jihan; ElHofy, Fatma; Al-Maary, Khalid S; Moussa, Ihab M I; Hessain, Ashgan M; Orabi, Ahmed; Saad, Alaa; Elhadidy, Mohamed

2017-05-10

The objectives of this study were to characterize the diversity and magnitude of antimicrobial resistance among Staphylococcus species recovered from imported beef meat sold in the Egyptian market and the potential mechanisms underlying the antimicrobial resistance phenotypes including harboring of resistance genes (mecA, cfr, gyrA, gyrB, and grlA) and biofilm formation. The resistance gene mecA was detected in 50% of methicillin-resistant non-Staphylococcus aureus isolates (4/8). Interestingly, our results showed that: (i) resistance genes mecA, gyrA, gyrB, grlA, and cfr were absent in Staphylococcus hominis and Staphylococcus hemolyticus isolates, although S. hominis was phenotypically resistant to methicillin (MR-non-S. aureus) while S. hemolyticus was resistant to vancomycin only; (ii) S. aureus isolates did not carry the mecA gene (100%) and were phenotypically characterized as methicillin- susceptible S. aureus (MSS); and (iii) the resistance gene mecA was present in one isolate (1/3) of Staphylococcus lugdunensis that was phenotypically characterized as methicillin-susceptible non-S. aureus (MSNSA). Our findings highlight the potential risk for consumers, in the absence of actionable risk management information systems, of imported foods and advice a strict implementation of international standards by different venues such as CODEX to avoid the increase in prevalence of coagulase positive and coagulase negative Staphylococcus isolates and their antibiotic resistance genes in imported beef meat at the Egyptian market.

Livestock-associated methicillin-resistant Staphylococcus aureus ST9 in pigs and related personnel in Taiwan.

PubMed

Fang, Hsin-Wei; Chiang, Po-Hsing; Huang, Yhu-Chering

2014-01-01

A livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) strain sequence type 398 (ST398) is found related to animals and humans in Europe and North America. To evaluate the nasal carriage of MRSA among pigs and related workers in Taiwan, we conducted this study. From June 25 to October 1 2012, a total of 641 and 100 nasal swabs were obtained from pigs and related workers, respectively, from 22 pig farms nationwide and 2 pig auction markets in Taiwan. All MRSA isolates were molecularly characterized. Overall, the nasal carriage rate of MRSA was 14.4% for pigs and 13% for humans. The carriage rate for pigs younger than 3 months was significantly higher than those older than 3 months (25.4% vs. 5.8%, p<.001). Percentage of MRSA-positive pig farms was 59.1% (13/22). The carriage rate for pigs in large-scale herds (≥ 10000 pigs) was significantly higher than that in small-scale (34.3% vs. 7.0%, p<.001) and that in auction markets (3.8%). The carriage rate was 19.2% (10/52) for pig farm workers, and the rate in large-scale farms was significantly higher than that in small-scale (36.8% vs. 9.1%, p = .014). Except for 3 isolates from humans, the other 99 isolates belonged to sequence type (ST) 9. 83 of 89 isolates from pigs shared a common pulsotype, which was also shared by 6 isolates from humans. More than 10% of pigs and related workers in Taiwan carried LA-MRSA ST9 in nares and cross-species transmission of LA-MRSA was documented by molecular methods.

Double triplex real-time PCR assay for simultaneous detection of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus haemolyticus and determination of their methicillin resistance directly from positive blood culture bottles.

PubMed

Kilic, Abdullah; Basustaoglu, A Celal

2011-12-01

We developed and validated here a double triplex real-time PCR assay to simultaneously detect and identify Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus and their methicillin resistance in a single reaction directly from Gram-positive cocci-in-clusters (GPCs)-positive blood culture bottles. From August 15, 2009 through February 15, 2010, 238 GPC-positive samples were collected and identified by conventional methods as 11 methicillin-resistant S. aureus (MRSA), 28 methicillin-susceptible S. aureus (MSSA), 176 MR coagulase-negative staphylococci (MRCoNS), 21 MSCoNS and two Enterococcus faecalis. The double triplex real-time PCR assay was targeted and detected tuf, nuc and mecA genes in the first tube and atlE, gap and mvaA genes in the second tube which could be run simultaneously. The detection limit of the assay was found at 10(3) CFU/ml for the atleE gene, 10(4) CFU/ml for the mva gene and 10(5) CFU/ml for gap, nuc, mecA and tuf genes based on seeding experiments. All Staphylococcus species except two S. epidermidis were correctly identified by the assay. The double triplex real-time PCR assay quickly and accurately detects S. aureus, S. epidermidis, S. hominis and S. haemolyticus and their methicillin resistance in a single reaction directly from positive blood culture bottles within 83 min. Copyright © 2011 Institut Pasteur. All rights reserved.

Multidrug-Resistant and Methicillin-Resistant Staphylococcus aureus (MRSA) in Hog Slaughter and Processing Plant Workers and Their Community in North Carolina (USA)

PubMed Central

Neyra, Ricardo Castillo; Frisancho, Jose Augusto; Rinsky, Jessica L.; Resnick, Carol; Carroll, Karen Colleen; Rule, Ana Maria; Ross, Tracy; You, Yaqi; Price, Lance B.

2014-01-01

Background: Use of antimicrobials in industrial food-animal production is associated with the presence of antimicrobial-resistant Staphylococcus aureus (S. aureus) among animals and humans. Hog slaughter/processing plants process large numbers of animals from industrial animal operations and are environments conducive to the exchange of bacteria between animals and workers. Objectives: We compared the prevalence of multidrug-resistant S. aureus (MDRSA) and methicillin-resistant S. aureus (MRSA) carriage among processing plant workers, their household members, and community residents. Methods: We conducted a cross-sectional study of hog slaughter/processing plant workers, their household members, and community residents in North Carolina. Participants responded to a questionnaire and provided a nasal swab. Swabs were tested for S. aureus, and isolates were tested for antimicrobial susceptibility and subjected to multilocus sequence typing. Results: The prevalence of S. aureus was 21.6%, 30.2%, and 22.5% among 162 workers, 63 household members, and 111 community residents, respectively. The overall prevalence of MDRSA and MRSA tested by disk diffusion was 6.9% and 4.8%, respectively. The adjusted prevalence of MDRSA among workers was 1.96 times (95% CI: 0.71, 5.45) the prevalence in community residents. The adjusted average number of antimicrobial classes to which S. aureus isolates from workers were resistant was 2.54 times (95% CI: 1.16, 5.56) the number among isolates from community residents. We identified two MDRSA isolates and one MRSA isolate from workers as sequence type 398, a type associated with exposure to livestock. Conclusions: Although the prevalence of S. aureus and MRSA was similar in hog slaughter/processing plant workers and their household and community members, S. aureus isolates from workers were resistant to a greater number of antimicrobial classes. These findings may be related to the nontherapeutic use of antimicrobials in food

Perception of Better Nasal Patency Correlates with Increased Mucosal Cooling after Surgery for Nasal Obstruction

NASA Astrophysics Data System (ADS)

Garcia, Guilherme; Sullivan, Corbin; Frank-Ito, Dennis; Kimbell, Julia; Rhee, John

2014-11-01

Nasal airway obstruction (NAO) is a common health problem with 340,000 patients undergoing surgery annually in the United States. Traditionally, otolaryngologists have focused on airspace cross-sectional areas and nasal resistance to airflow as objective measures of nasal patency, but neither of these variables correlated consistently with patients' symptoms. Given that the sensation of nasal airflow is also associated with mucosal cooling (i.e., heat loss) during inspiration, we investigated the correlation between the sensation of nasal obstruction and mucosal cooling in 10 patients before and after NAO surgery. Three-dimensional models of the nasal anatomy were created based on pre- and post-surgery computed tomography scans. Computational fluid dynamics (CFD) simulations were conducted to quantify nasal resistance and mucosal cooling. Patient-reported symptoms were measured by a visual analog scale and the Nasal Obstruction Symptom Evaluation (NOSE), a disease-specific quality of life questionnaire. Our results revealed that the subjective sensation of nasal obstruction correlated with both nasal resistance and heat loss, but the strongest correlation was between the NOSE score and the nasal surface area where heat flux exceeds 50 W /m2 . In conclusion, a significant post-operative increase in mucosal cooling correlates well with patients' perception of better nasal patency after NAO surgery.

[Staphylococcus aureus carrying Panton-Valentine leukocidin genes nasal colonization and skin infection: screening in case of outbreak in a school environment].

PubMed

Carré, N; Sillam, F; Dabas, J-P; Herbreteau, N; Pinchon, C; Ortmans, C; Thiolet, J-M; Vandenesch, F; Coignard, B

2008-09-01

An outbreak of Staphylococcus aureus (SA) carrying the gene coding for Panton-Valentine leukocidin (PVL) skin infections in a primary school was investigated and monitored in the Val-d'Oise region (Greater Paris) in 2006. Skin infections reported after the beginning of the school year in primary-school teachers, students and their relatives were diagnosed and treated at the local hospital and screening for nasal colonization was implemented. A patient presenting with folliculitis, an abscess or furuncle with a positive-skin test or nasal swab for SA-PV was considered to be a case of infection. Colonization was defined as identification of SA-PVL in a nasal swab in the absence of skin lesions. In addition to recommended control measures, treatment by topical intranasal mupirocin was prescribed to all colonized patients and relatives of infected patients. Over five months, 22 cases of PVL-positive SA skin infections, including a case of simple folliculitis, were confirmed in 15 primary-school students (attack rate=18.5%) and seven relatives. The occurrence of nasal colonization in relatives not attending the same school ranged from 0 to 30% according to the number of cases of skin infection in the family (p<0,01). Two-thirds of patients treated with mupirocin were decolonized. Transmission of this SA strain in school and family environments confirms the epidemic potential of PVL-positive isolates; however, screening for nasal colonization should be restricted to cases of skin infection and people in their immediate environment.

[Clinical effects of nasal glucocorticoid on amelioration of nasal obstruction in patients with persistent non-allergic rhinitis].

PubMed

Sail, Giyab A; Zuo, Ke-jun; Xu, Geng

2009-09-01

To observe the efficacy of nasal glucocorticoid continuously used for 12 weeks on nasal obstruction in patients with persistent non-allergic rhinitis (PNAR). The changes of nasal obstruction, nasal resistance, nasal mucous membrane and quality of life in 47 patients with PNAR were observed. The efficacy of nasal glucocorticoid (Mometasone Furoate Nasal Spray, MFNS 200 microg/day) on patients with PNAR was evaluated. The results of nasal glucocorticoid (MFNS) continuously used for 12 weeks demonstrated: (1) After treatment, the nasal obstruction, nasal discharge, nasal obstruction related dizziness, headache, hyposmia, daily life activity, whole body fatigue, mental status were significantly improved (P < 0.05). (2) Nasal resistance showed significant amelioration (pre-treatment = 0.28 +/- 0.10, post- treatment = 0.16 +/- 0.05; F = 91.471, P < 0.05). (3) SF-36 questionnaire revealed that role physical, bodily pain, general health, role emotional had significant amelioration (P < 0.01). (4) SNOT-20 questionnaire revealed that the defatigation, impaired concentration, pinch the nose, nasal discharging into the throat, sleep quality had significant amelioration (P < 0.01). (5) Continued treatment for 12 weeks was better than 4 weeks, continued treatment had good effect. The study shows that nasal glucocorticoid improved the nasal obstruction, nasal resistance, nasal mucous membrane and quality of life in patients with PNAR.

Changes of Antimicrobial Resistance among Staphylococcus Aureus Isolated in 8 Consecutive Years in the First Bethune Hospital

NASA Astrophysics Data System (ADS)

Xu, Wei; Zhou, Qi; Yang, Chunguang; Yao, Hanxin; Xu, Jiancheng

This study was to investigate the antimicrobial resistance of Staphylococcus aureus isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 1469 strains of Staphylococcus aureus were collected from sputum 705 (18.0%), secretions 206 (14.0%), pus 177 (12.0%) during the past 8 years. The rates of methicillin-resistant Staphylococcus aureus (MRSA) were between 50.8% and 83.3% during the past 8 years, respectively. In recent 8 years, the antimicrobial resistance of Staphylococcus aureus had increased. Monitoring the antimicrobial resistance to Staphylococcus aureus should be strengthened. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

In vitro efficacy of a honey-based gel against canine clinical isolates of Staphylococcus pseudintermedius and Malassezia pachydermatis.

PubMed

Oliveira, Ana M P; Devesa, Joana S P; Hill, Peter B

2018-03-22

Staphylococcus pseudintermedius and Malassezia pachydermatis are important agents in canine pyoderma and otitis. Determine the in vitro efficacy of a honey-based gel (HBO) against meticillin-susceptible S. pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP) and M. pachydermatis, by minimum bactericidal concentration (MBC), minimum fungicidal concentration (MFC) and time-kill assay (TKA). Efficacy of the product's honey component (HO) also was evaluated. Sixty S. pseudintermedius and 10 M. pachydermatis canine isolates were selected. All isolates were tested against serial dilutions of an HBO containing 40% HO (40%, 20%, 10%, 5% and 2.5% w/v) and HO alone (undiluted, 40%, 20%, 10%, 5% and 2.5% w/v). Microbroth assay followed by subculture was used to determine MBC and MFC. The same protocol was applied after product exposure to catalase. A well-diffusion assay for S. pseudintermedius was used to generate inhibition zones. A TKA for 10 isolates of S. pseudintermedius and 10 isolates of M. pachydermatis was performed. MBC was 20% w/v (5-20% w/v) for HBO and HO. HBO had lower MBC values when compared to HO (P = 0.003). No statistical difference was observed between MSSP/MRSP isolates (HBO P = 0.757, HO P = 0.743). Only HO was affected by catalase (P = 0.015). MFC for HBO was 10% w/v (5-10% w/v) and 40% w/v for HO (20-≥40% w/v). All isolates were killed after 4 h of exposure. Staphylococcus pseudintermedius and M. pachydermatis are susceptible to the HBO and these results can be used for future clinical trials. © 2018 ESVD and ACVD.

Characterization of methicillin-resistant Staphylococcus spp. isolated from dogs in Korea.

PubMed

Jang, Yunho; Bae, Dong hwa; Cho, Jae-Keun; Bahk, Gyung Jin; Lim, Suk-Kyung; Lee, Young Ju

2014-11-01

Staphylococci were isolated from dogs in animal hospitals, animal shelters, and the Daegu PET EXPO to investigate the characteristics of circulating methicillin-resistant Staphylococcal (MRS) strains in companion animals in Korea. A total of 36/157 isolates were classified as MRS, and subdivided as follows: 1 methicillin-resistant Staphylococcus aureus (MRSA), 4 methicillin-resistant Staphylococcus epidermidis, 2 methicillin-resistant Staphylococcus haemolyticus, and 29 MRS spp. Among the 36 MRS isolates tested, 100% were resistant to oxacillin and penicillin, and at least 50% were resistant to sulfamethoxazole/trimethoprim (69.4%), erythromycin (63.9%), tetracycline (58.3%), cefoxitin (55.6%), clindamycin (50.0%) or pirlimycin (50.0%). Additionally, 34/36 MRS isolates (94.4%) were mecA positive, 15 of which were further classified as SCCmec type V, 6 isolates as type I, 4 isolates as type IIIb, 1 isolate as type IVa, 1 isolate as type IV, with 7 isolates being non-classifiable. The results of multilocus sequence typing and spa typing for the one MRSA strain were ST 72 (1-4-1-8-4-4-3) and spa t148. Our results provide evidence that companion animals like dogs may be MRS carriers, and that continued surveillance of MRS in companion animals is required to prevent increased incidences in humans.

Species diversity and antibiotic resistance properties of Staphylococcus of farm animal origin in Nkonkobe Municipality, South Africa.

PubMed

Adegoke, Anthony A; Okoh, Anthony I

2014-03-01

The occurrence and antibiotic susceptibility profile of Staphylococcus isolates of healthy farm animal origin in Nkonkobe Municipality as well as the prevalence of putative antibiotic resistance genes were investigated using phenotypic and molecular methods. A total of 120 Staphylococcus isolates were isolated from 150 animal samples and consisted of Staphylococcus haemolyticus (30 %) and Staphylococcus aureus (23.3 %) from pig, Staphylococcus capitis (15 %) from goat, S. haemolyticus (5 %) and Staphylococcus xylosus (15 %) from cattle, and other staphylococci (11.7 %) from dead chicken and pigs. Besides this, the presence of these isolates was observed from the animal dung, showing that the organisms are shed to the environment. About 23.3 % of these isolates were coagulase-positive and 76.7 % were coagulase-negative Staphylococcus. Between 75 and 100 % of the isolates were resistant to penicillin G, tetracycline, sulfamethoxazole, and nalidixic acid; about 38 % were methicillin-resistant staphylococci, including 12.6 % methicillin-resistant S. aureus from pigs. In total, 12 % of all isolates were vancomycin resistant. Also, 12 % of the isolates were erythromycin resistant, while 40.2 % were resistant to ceftazidime. Only the genes mecA and mphC could be confirmed, whereas the genes vanA, vanB, ermA, ermB, and ermC could not be detected. The high phenotypic antibiotic resistance and the presence of some associated resistance genes is a potential threat to public health and suggest the animals to be important reservoirs of antibiotic resistance determinants in the environment.

Nasal carriage of enterotoxin-producing Staphylococcus aureus among restaurant workers in Kuwait City.

PubMed Central

al Bustan, M. A.; Udo, E. E.; Chugh, T. D.

1996-01-01

Enterotoxin-producing Staphylococcus aureus is a common cause of staphylococcal food poisoning. To determine the incidence of carriage of enterotoxin-producing S. aureus in a sample of the healthy population in Kuwait city, restaurant workers in the city were screened for nasal carriage of S. aureus. 26.6% of 500 workers studied carried S. aureus and 86.6% of the S. aureus produced staphylococcal enterotoxins. 28% produced enterotoxin A, 28.5% produced enterotoxin B, 16.4% produced enterotoxin C and 3.5% produced enterotoxin D. Ten isolates produced both enterotoxins A and B or A and C. 73% of the isolates were untypeable with standard phages. However, 17.1%, 3% and 6% belonged to phage groups I, II and III respectively. The results demonstrated a high level of enterotoxigenic S. aureus carriage among restaurant workers which although lower than that reported for the general population and hospital workers may be important in the restaurant industry. PMID:8666076

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand.

PubMed

Patchanee, Prapas; Tadee, Pakpoom; Arjkumpa, Orapun; Love, David; Chanachai, Karoon; Alter, Thomas; Hinjoy, Soawapak; Tharavichitkul, Prasit

2014-12-01

This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand

PubMed Central

Tadee, Pakpoom; Arjkumpa, Orapun; Love, David; Chanachai, Karoon; Alter, Thomas; Hinjoy, Soawapak; Tharavichitkul, Prasit

2014-01-01

This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand. PMID:25530702

Minimum inhibitory concentration and killing properties of rifampicin against canine Staphylococcus pseudintermedius isolates from dogs in the southeast USA.

PubMed

Ho, Karen K; Conley, Austin C; Kennis, Robert A; Hathcock, Terri L; Boothe, Dawn M; White, Amelia G

2018-05-29

Meticillin-resistant (MR) staphylococcal pyoderma in dogs has led to increased use of alternate antibiotics such as rifampicin (RFP). However, little information exists regarding its pharmacodynamics in MR Staphylococcus pseudintermedius. To determine the minimum inhibitory concentration (MIC) and killing properties of RFP for canine Staphylococcus pseudintermedius isolates. The MIC of RFP was determined using the ETEST ® for 50 meticillin-susceptible (MS) and 50 MR S. pseudintermedius isolates collected from dogs. From these isolates, two MS isolates (RFP MIC of 0.003 and 0.008 μg/mL, respectively) and two MR isolates (RFP MIC of 0.003 and 0.012 μg/mL, respectively) were subjected to time-kill studies. Mueller-Hinton broth was supplemented with RFP at 0, 0.5, 1, 2, 4, 8, 16 and 32 times the MIC for 0, 2, 4, 10, 16 and 24 h. The number of viable colony forming units in each sample was determined using a commercial luciferase assay kit. The MIC 50 and MIC 90 were the same for MS and MR isolates, at 0.004 μg/mL and 0.008 μg/mL, respectively. Rifampicin kill curves were not indicative of concentration-dependency, suggesting time-dependent activity. Two isolates (MS 0.003 and 0.008 μg/mL) exhibited bacteriostatic activity, whereas two others (MR 0.003 and 0.012 μg/mL) exhibited bactericidal activity. This study demonstrated that MS and MR S. pseudintermedius isolates were equally susceptible to rifampicin and that dosing intervals should be designed for time-dependent efficacy. These data can support pharmacokinetic studies of RFP in dogs with susceptible infections caused by S. pseudintermedius. © 2018 ESVD and ACVD.

A study of Staphylococcus aureusnasal carriage, antibacterial resistance and virulence factor encoding genes in a tertiary care hospital, Kayseri, Turkey.

PubMed

Oguzkaya-Artan, M; Artan, C; Baykan, Z; Sakalar, C; Turan, A; Aksu, H

2015-01-01

This study was to determine the virulence encoding genes, and the antibiotic resistance patterns of the Staphylococcus aureus isolates, which were isolated from the nasal samples of chest clinic patients. The nasal samples of the in-patients (431) and out-patients (1857) in Kayseri Training and Research Hospital's Chest Clinic, Kayseri, Turkey, were cultured on CHROMagar (Biolife, Italiana) S. aureus, and subcultured on sheep blood agar for the isolation of S. aureus. Disc diffusion method was used for antimicrobial susceptibility testing. The occurrence of the staphylococcal virulence encoding genes (enterotoksins [sea, seb, sec, see, seg, seh, sei, sej], fibronectin-binding proteins A, B [fnbA, fnbB], toxic shock syndrome toxin-1 [tst]) were detected by polymerase chain reaction. Forty-five of the 55 (81.8%) S. aureus isolates from inpatients, and 319 (90.6%) isolates from tested 352 out-patient's isolates were suspected to all the antibiotics tested. methicillin-resistant S. aureus (MRSA) was detected in 1.2% of S. aureus isolates. Rifampin, trimethoprim-sulfamethoxazole, clindamycin, erythromycin, gentamicin resistance rates were 1.2%, 1.7%, 2.0%, 8.8%, and 1.2%, respectively. The isolates were susceptible to teicoplanin and vancomycin. The genes most frequently found were tst (92.7%), seg (85.8%), sea (83.6%), fnbA (70.9%). There was no statistical significance detected between MRSA and mecA-negative S. aureus isolates in encoding genes distribution (P > 0.05). Our results show that virulence factor encoding genes were prevalent in patients with S. aureus carriage, whereas antibiotic resistance was low. These virulence determinants may increase the risk for subsequent invasive infections in carriers.

Nasal microenvironments and interspecific interactions influence nasal microbiota complexity and S. aureus carriage.

PubMed

Yan, Miling; Pamp, Sünje J; Fukuyama, Julia; Hwang, Peter H; Cho, Do-Yeon; Holmes, Susan; Relman, David A

2013-12-11

The indigenous microbiota of the nasal cavity plays important roles in human health and disease. Patterns of spatial variation in microbiota composition may help explain Staphylococcus aureus colonization and reveal interspecies and species-host interactions. To assess the biogeography of the nasal microbiota, we sampled healthy subjects, representing both S. aureus carriers and noncarriers at three nasal sites (anterior naris, middle meatus, and sphenoethmoidal recess). Phylogenetic compositional and sparse linear discriminant analyses revealed communities that differed according to site epithelium type and S. aureus culture-based carriage status. Corynebacterium accolens and C. pseudodiphtheriticum were identified as the most important microbial community determinants of S. aureus carriage, and competitive interactions were only evident at sites with ciliated pseudostratified columnar epithelium. In vitro cocultivation experiments provided supporting evidence of interactions among these species. These results highlight spatial variation in nasal microbial communities and differences in community composition between S. aureus carriers and noncarriers. Copyright © 2013 Elsevier Inc. All rights reserved.

Nasal microenvironments and interspecific interactions influence nasal microbiota complexity and S. aureus carriage

PubMed Central

Yan, Miling; Pamp, Sünje J.; Fukuyama, Julia; Hwang, Peter H.; Cho, Do-Yeon; Holmes, Susan; Relman, David A.

2013-01-01

Summary The indigenous microbiota of the nasal cavity plays important roles in human health and disease. Patterns of spatial variation in microbiota composition may help explain Staphylococcus aureus colonization, and reveal interspecies and species-host interactions. To assess the biogeography of the nasal microbiota, we sampled healthy subjects, representing both S. aureus carriers and non-carriers, at 3 nasal sites (anterior naris, middle meatus, and sphenoethmoidal recess). Phylogenetic compositional and sparse linear discriminant analyses revealed communities that differed according to site epithelium type and S. aureus culture-based carriage status. Corynebacterium accolens and C. pseudodiphtheriticum were identified as the most important microbial community determinants of S. aureus carriage, with competitive interactions evident only at sites with ciliated pseudostratified columnar epithelium. In vitro co-cultivation experiments provided supporting evidence of interactions among these species. These results highlight spatial variation in nasal microbial communities and differences in community composition between S. aureus carriers and non-carriers. PMID:24331461

Changes in nasal airflow and heat transfer correlate with symptom improvement after surgery for nasal obstruction.

PubMed

Kimbell, J S; Frank, D O; Laud, Purushottam; Garcia, G J M; Rhee, J S

2013-10-18

Surgeries to correct nasal airway obstruction (NAO) often have less than desirable outcomes, partly due to the absence of an objective tool to select the most appropriate surgical approach for each patient. Computational fluid dynamics (CFD) models can be used to investigate nasal airflow, but variables need to be identified that can detect surgical changes and correlate with patient symptoms. CFD models were constructed from pre- and post-surgery computed tomography scans for 10 NAO patients showing no evidence of nasal cycling. Steady-state inspiratory airflow, nasal resistance, wall shear stress, and heat flux were computed for the main nasal cavity from nostrils to posterior nasal septum both bilaterally and unilaterally. Paired t-tests indicated that all CFD variables were significantly changed by surgery when calculated on the most obstructed side, and that airflow, nasal resistance, and heat flux were significantly changed bilaterally as well. Moderate linear correlations with patient-reported symptoms were found for airflow, heat flux, unilateral allocation of airflow, and unilateral nasal resistance as a fraction of bilateral nasal resistance when calculated on the most obstructed nasal side, suggesting that these variables may be useful for evaluating the efficacy of nasal surgery objectively. Similarity in the strengths of these correlations suggests that patient-reported symptoms may represent a constellation of effects and that these variables should be tracked concurrently during future virtual surgery planning. © 2013 Elsevier Ltd. All rights reserved.

Prevalence of Staphylococcus, including Methicillin-Resistant Staphylococcus aureus, in a Physical Therapy Education Facility.

PubMed

Dhagat, Priya V; Gibbs, Karen A; Rohde, Rodney E

2015-01-01

The purpose of this study was to assess the prevalence of Staphylococcus species, including methicillin-resistant Staphylococcus aureus (MRSA), in a physical therapy (PT) education facility. The PT laboratory classrooms were routinely used by graduate PT students and faculty, undergraduate anatomy students, and licensed practitioners for continuing education purposes. A total of 88 swab samples were collected from plinths and other equipment and plated onto mannitol salt agar (MSA). Suspected S. aureus colonies were confirmed by Staphyloslide latex testing. S. aureus isolates were plated to HardyCHROM agar to identify MRSA. VITEK antibiotic susceptibility testing confirmed MRSA isolates. Forty-seven samples showed growth (47/88, 53%), and 7 tested positive for S. aureus (7/47, 15%). Of those 7, one demonstrated oxacillin resistance and was confirmed as MRSA (1/7, 2%). Remaining samples grew other species of Staphylococcus and gram-negative bacilli. Given high classroom utilization, staphylococci environmental prevalence would be expected. However, the presence of MRSA was unexpected. Results demonstrate the potential for easily transmissible and potentially harmful organisms to be present in multi-use classrooms utilized by health professions students where frequent skin-to-skin contact occurs. Strict, routine cleaning of plinths and other equipment is imperative in reducing exposure risk.

Nasal Colonisation by Staphylococcus aureus Depends upon Clumping Factor B Binding to the Squamous Epithelial Cell Envelope Protein Loricrin

PubMed Central

Mulcahy, Michelle E.; Geoghegan, Joan A.; Monk, Ian R.; O'Keeffe, Kate M.; Walsh, Evelyn J.

2012-01-01

Staphylococcus aureus asymptomatically colonises the anterior nares, but the host and bacterial factors that facilitate colonisation remain incompletely understood. The S. aureus surface protein ClfB has been shown to mediate adherence to squamous epithelial cells in vitro and to promote nasal colonisation in both mice and humans. Here, we demonstrate that the squamous epithelial cell envelope protein loricrin represents the major target ligand for ClfB during S. aureus nasal colonisation. In vitro adherence assays indicated that bacteria expressing ClfB bound loricrin most likely by the “dock, lock and latch” mechanism. Using surface plasmon resonance we showed that ClfB bound cytokeratin 10 (K10), a structural protein of squamous epithelial cells, and loricrin with similar affinities that were in the low µM range. Loricrin is composed of three separate regions comprising GS-rich omega loops. Each loop was expressed separately and found to bind ClfB, However region 2 bound with highest affinity. To investigate if the specific interaction between ClfB and loricrin was sufficient to facilitate S. aureus nasal colonisation, we compared the ability of ClfB+ S. aureus to colonise the nares of wild-type and loricrin-deficient (Lor−/−) mice. In the absence of loricrin, S. aureus nasal colonisation was significantly impaired. Furthermore a ClfB− mutant colonised wild-type mice less efficiently than the parental ClfB+ strain whereas a similar lower level of colonisation was observed with both the parental strain and the ClfB− mutant in the Lor−/− mice. The ability of ClfB to support nasal colonisation by binding loricrin in vivo was confirmed by the ability of Lactococcus lactis expressing ClfB to be retained in the nares of WT mice but not in the Lor−/− mice. By combining in vitro biochemical analysis with animal model studies we have identified the squamous epithelial cell envelope protein loricrin as the target ligand for ClfB during nasal

The Impact of a Universal Decolonization Protocol on Hospital-Acquired Methicillin-Resistant Staphylococcus aureus in a Burn Population.

PubMed

Johnson, Arthur T; Nygaard, Rachel M; Cohen, Ellie M; Fey, Ryan M; Wagner, Anne Lambert

Hospital-acquired (HA) methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of HA infections and a significant concern for burn centers. The use of 2% chlorhexidine-impregnated wipes and nasal mupirocin significantly decreases the rate of HA-MRSA in adult intensive care units. The aim of this study was to examine the impact of universal decolonization on the rate of MRSA conversion in an American Burn Association verified adult and pediatric burn center. Universal decolonization protocol consisting of daily chlorhexidine baths and a 5-day course of nasal mupirocin was implemented in the burn unit. MRSA screening both on admission and weekly and contact isolation practices were in place in pre-decolonization and post-decolonization periods. Patient data were analyzed 2 years before and 1 year after implementation of the protocol. The incidence rate of MRSA was significantly decreased after the implementation of the decolonization protocol (11.8 vs 1.0 per 1000 patient days, P < .001). Secondary to the loss of the skin barrier and suppressed immune systems, burn patients are at greater risk for invasive infection leading to severe complications and death. The prevalence of HA-MRSA at our institution's burn center was significantly decreased after the implementation of a universal decolonization protocol.

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398.

PubMed

Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-05-01

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1-5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that

Comparison of Real-Time PCR and Conventional Biochemical Methods for Identification of Staphylococcus lugdunensis▿

PubMed Central

Pinsky, Benjamin A.; Samson, Divinia; Ghafghaichi, Laleh; Baron, Ellen J.; Banaei, Niaz

2009-01-01

Staphylococcus lugdunensis is an aggressive, virulent member of the coagulase-negative staphylococci (CoNS) that is responsible for severe, rapidly progressive skin and soft tissue infections and native valve endocarditis. To facilitate prompt identification and appropriate therapy, we describe here a rapid and robust multiplex real-time PCR assay that is able to definitively distinguish S. lugdunensis from other staphylococci. Using melting curve analysis, the assay also identifies Staphylococcus aureus and CoNS other than S. lugdunensis and determines MecA-dependent resistance to methicillin (meticillin). When applied to a panel of well-characterized staphylococcal reference strains, as well as 165 clinical isolates previously identified by conventional methods, the assay was both sensitive and specific for S. lugdunensis, correctly identifying the reference strain and all 47 S. lugdunensis isolates without inappropriate amplification of other staphylococci. Furthermore, rapid biochemical identification using the WEE-TAB system to detect ornithine decarboxylase activity was found to be unsuitable as an alternative to PCR identification, displaying just 31% sensitivity and 77% specificity when tested on a subset (90 isolates) of the clinical strains. We therefore propose that this simple, accurate PCR approach will allow for the routine and timely identification of S. lugdunensis in the clinical microbiology laboratory. PMID:19741081

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

PubMed

Longhurst, William D; Sheele, Johnathan M

2018-05-01

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis is extremely rare and has a high mortality rate. We report a case of MRSA meningitis in an otherwise healthy young adult female with no recent trauma or neurosurgical interventions. Despite antibiotics she suffered a vasculitis-induced cerebral vascular ischemic event. Copyright © 2018 Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus (MRSA) in slaughtered pigs and abattoir workers in Italy.

PubMed

Normanno, Giovanni; Dambrosio, Angela; Lorusso, Vanessa; Samoilis, Georgios; Di Taranto, Pietro; Parisi, Antonio

2015-10-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen present in the hospital environment (HA-MRSA), in the community (CA-MRSA) and in livestock, including pigs (LA-MRSA). MRSA may enter the human food chain during slaughtering and may infect humans coming into direct contact with pigs or pork products. This study aimed to determine the prevalence and characteristics of MRSA isolated from pigs and workers at industrial abattoirs in southern Italy. A total of 215 pig nasal swabs were screened for the presence of MRSA using PCR. An MRSA isolate was detected from each mecA/nuc PCR-positive sample and characterized by spa-typing, Multi-Locus Sequence Typing, SCC-mec and Panton-Valentine Leukocidin (PVL), and also tested for the production of staphylococcal enterotoxins (SEs). Eighty-one MRSA isolates (37.6%) were obtained from the 215 pig nasal swabs; 37 of these isolates were further characterized, and showed 18 different spa-types and 8 different STs. The most frequently recovered STs were ST398 (CC398-t034, t011, t899, t1939 - 43.2%) followed by ST8 (CC8-t008, t064, t2953, t5270 - 24.3%) and ST1 (CC1-t127, t174, t2207 - 10.8%). Nine MRSA isolates were obtained from the 113 human swabs; the isolates showed 5 different spa-types and 5 different STs, including the novel ST2794 (t159). The most representative STs recovered were ST1 (CC1-t127) and ST398 (CC398-t034) (33.3%). None of the MRSA isolates showed the ability to produce SEs and PVL and all resulted resistant to two or more classes of antimicrobials. This study shows the great genetic diversity of MRSA strains in slaughtered pigs and in abattoir employees in Italy, and clearly demonstrates the need for improved hygiene standards to reduce the risk of occupational and food-borne infection linked to the handling/consumption of raw pork containing MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antimicrobial resistance and population structure of Staphylococcus epidermidis recovered from animals and humans.

PubMed

Argudín, M Angeles; Vanderhaeghen, Wannes; Vandendriessche, Stien; Vandecandelaere, Ilse; André, François-Xavier; Denis, Olivier; Coenye, Tom; Butaye, Patrick

2015-07-09

While Staphylococcus epidermidis, as part of the commensal flora, is a well-known human opportunistic pathogen, only little is known about the genetic relatedness of S. epidermidis carriage isolates from animal and human origin. This study aimed to compare S. epidermidis recovered from livestock, livestock-farmers and humans associated with the hospital environment. A total of 193 S. epidermidis isolates from three populations [animals (n=33), farmers (n=86) and hospital-associated (n=74)] were characterized by broth microdilution antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The overall S. epidermidis nasal colonization rate was low in animals (1-9%) but high among farmers (75%). High levels of multi-resistance were found in all populations. Tetracycline resistance was high in animal and farmer isolates; resistance to erythromycin, clindamycin and trimethoprim was high in animal and hospital-associated isolates. Methicillin-resistant S. epidermidis - MRSE isolates were found in all collections, with 22 (67%) MRSE in animals, 44 (51%) MRSE in farmers and 42 (57%) MRSE associated with the hospital-setting. Known SCCmec types and variants were detected in 79% of MRSE; the rest were non-typeable cassettes. In total 79 PFGE-types were found, of which 22 were shared between livestock, farmers and the hospital settings. Clonal complex 2 was predominant in all three populations and most STs corresponded to types previously observed in community and nosocomial S. epidermidis populations. S. epidermidis isolates from livestock, farmers and hospital-setting showed a high level of diversity, but some clones can be found in humans as well as in animals. Copyright © 2015 Elsevier B.V. All rights reserved.

Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary Report 2014

DTIC Science & Technology

2015-10-01

NAVY AND MARINE CORPS PUBUC IEAI.TI CINTIR PREVENTION AND PROTECTION START HERE Methicillin-Resistant Staphylococcus aureus IMRSAJ Infections in...Methicit li~esistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (000): Annual Summary Report 2014 Jessica Spencer. Uzo...Distribution is not limited. NUMBER NMCPHC-EOC-TR-499-2015 NUMBER($) NMCPHC-EDC-TR-499-201 5 Metticitrin-resistant Staphylococcus aureus (MRSA

Vancomycin Resistance in Staphylococcus aureus


PubMed Central

McGuinness, Will A.; Malachowa, Natalia; DeLeo, Frank R.

2017-01-01

The evolution of Staphylococcus aureus during the modern antibiotic era has been delineated by distinct strain emergence events, many of which include acquisition of antibiotic resistance. The relative high burden of methicillin-resistant S. aureus (MRSA) in healthcare and community settings is a major concern worldwide. Vancomycin, a glycopeptide antibiotic that inhibits cell wall biosynthesis, remains a drug of choice for treatment of severe MRSA infections. S. aureus strains exhibiting increased resistance to vancomycin, known as vancomycin intermediate-resistant S. aureus (VISA) (MIC = 4-8 µg/mL), were discovered in the 1990s. The molecular basis of resistance in VISA is polygenic and involves stepwise mutations in genes encoding molecules predominantly involved in cell envelope biosynthesis. S. aureus isolates with complete resistance to vancomycin (MIC ≥ 16 µg/mL) are termed vancomycin-resistant S. aureus (VRSA)—they were first reported in the U.S. in 2002. Resistance in VRSA is conferred by the vanA gene and operon, which is present on a plasmid. Although treatment of VRSA infections is challenging, the total number of human VRSA infections to date is limited (14 in the U.S.). By comparison, the burden of VISA is relatively high and the molecular mechanisms of resistance are less well-defined. VISA are associated with persistent infections, vancomycin treatment failure, and poor clinical outcomes. Here, we review in brief progress made toward understanding the acquisition of antibiotic resistance in S. aureus, with an emphasis on the molecular mechanisms underlying vancomycin resistance. PMID:28656013

Vancomycin Resistance in Staphylococcus aureus
.

PubMed

McGuinness, Will A; Malachowa, Natalia; DeLeo, Frank R

2017-06-01

The evolution of Staphylococcus aureus during the modern antibiotic era has been delineated by distinct strain emergence events, many of which include acquisition of antibiotic resistance. The relative high burden of methicillin-resistant S. aureus (MRSA) in healthcare and community settings is a major concern worldwide. Vancomycin, a glycopeptide antibiotic that inhibits cell wall biosynthesis, remains a drug of choice for treatment of severe MRSA infections. S. aureus strains exhibiting increased resistance to vancomycin, known as vancomycin intermediate-resistant S. aureus (VISA) (MIC = 4-8 µg/mL), were discovered in the 1990s. The molecular basis of resistance in VISA is polygenic and involves stepwise mutations in genes encoding molecules predominantly involved in cell envelope biosynthesis. S. aureus isolates with complete resistance to vancomycin (MIC ≥ 16 µg/mL) are termed vancomycin-resistant S. aureus (VRSA)-they were first reported in the U.S. in 2002. Resistance in VRSA is conferred by the vanA gene and operon, which is present on a plasmid. Although treatment of VRSA infections is challenging, the total number of human VRSA infections to date is limited (14 in the U.S.). By comparison, the burden of VISA is relatively high and the molecular mechanisms of resistance are less well-defined. VISA are associated with persistent infections, vancomycin treatment failure, and poor clinical outcomes. Here, we review in brief progress made toward understanding the acquisition of antibiotic resistance in S. aureus , with an emphasis on the molecular mechanisms underlying vancomycin resistance.

Impact of infection control interventions on rates of Staphylococcus aureus bacteraemia in National Health Service acute hospitals, East Midlands, UK, using interrupted time-series analysis.

PubMed

Newitt, S; Myles, P R; Birkin, J A; Maskell, V; Slack, R C B; Nguyen-Van-Tam, J S; Szatkowski, L

2015-05-01

Reducing healthcare-associated infection (HCAI) is a UK national priority. Multiple national and regional interventions aimed at reduction have been implemented in National Health Service acute hospitals, but assessment of their effectiveness is methodologically challenging. To assess the effectiveness of national and regional interventions undertaken between 2004 and 2008 on rates of meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-sensitive Staphylococcus aureus (MSSA) bacteraemia within acute hospitals in the East Midlands, using interrupted time-series analysis. We used segmented regression to compare rates of MRSA and MSSA bacteraemia in the pre-intervention, implementation, and post-intervention phases for combined intervention packages in eight acute hospitals. Most of the change in MSSA and MRSA rates occurred during the implementation phase. During this phase, there were significant downward trends in MRSA rates for seven of eight acute hospital groups; in four, this was a steeper quarter-on-quarter decline compared with the pre-intervention phase, and, in one, an upward trend in the pre-intervention phase was reversed. Regarding MSSA, there was a significant positive effect in four hospital groups: one upward trend during the pre-intervention phase was reversed, two upward trends plateaued, and in one hospital group an indeterminate trend decreased significantly. However, there were significant increasing trends in quarterly MSSA rates in four hospital groups during the implementation or post-intervention periods. The impact of interventions varied by hospital group but the overall results suggest that national and regional campaigns had a beneficial impact on MRSA and MSSA bacteraemia within the East Midlands. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Molecular characterization and antibiotic resistance of Staphylococcus spp. isolated from cheese processing plants.

PubMed

Rodrigues, Marjory Xavier; Silva, Nathália Cristina Cirone; Trevilin, Júlia Hellmeister; Cruzado, Melina Mary Bravo; Mui, Tsai Siu; Duarte, Fábio Rodrigo Sanches; Castillo, Carmen J Contreras; Canniatti-Brazaca, Solange Guidolin; Porto, Ernani

2017-07-01

The aim of this research paper was to characterize coagulase-positive and coagulase-negative staphylococci from raw milk, Minas cheese, and production lines of Minas cheese processing. One hundred isolates from 3 different cheese producers were characterized using molecular approaches, such as PCR, molecular typing, and DNA sequencing. Staphylococcus aureus (88% of the isolates) was the most abundant followed by Staphylococcus epidermidis, Staphylococcus hyicus, and Staphylococcus warneri. Among the 22 enterotoxin genes tested, the most frequent was seh (62% of the isolates), followed by selx and ser. Hemolysin genes were widely distributed across isolates, and Panton-Valentine leukocidin and toxic shock syndrome toxin genes were also identified. Methicillin-resistant S. aureus were staphylococcal cassette chromosome mec III, IVa, IVd, and others nontypeable. In the phenotypic antibiotic resistance, multiresistant isolates were detected and resistance to penicillin was the most observed. Using spa typing, we identified several types and described a new one, t14969, isolated from cheese. These findings suggest that antibiotic resistance and potentially virulent strains from different sources can be found in the Brazilian dairy processing environment. Further research should be conducted with collaboration from regulatory agencies to develop programs of prevention of virulent and resistant strain dissemination in dairy products and the processing environment. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus, Western Australia

PubMed Central

Dailey, Lynne; Coombs, Geoffrey W.; O'Brien, Frances G.; Pearman, John W.; Christiansen, Keryn; Grubb, Warren B.

2005-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a notable cause of hospital-acquired infections. A statewide screening and control policy was implemented in Western Australia (WA) after an outbreak of epidemic MRSA in a Perth hospital in 1982. We report on statutory notifications from1998 to 2002 and review the 20-year period from 1983 to 2002. The rate of reporting of community-associated Western Australia MRSA (WAMRSA) escalated from 1998 to 2002 but may have peaked in 2001. Several outbreaks were halted, but they resulted in an increase in reports as a result of screening. A notable increase in ciprofloxacin resistance during the study period was observed as a result of more United Kingdom epidemic MRSA (EMRSA) -15 and -16. WA has seen a persistently low incidence of multidrug-resistant MRSA because of the screening and decolonization program. Non–multidrug-resistant, community-associated WAMRSA strains have not established in WA hospitals. PMID:16318700

Oxacillin sensitization of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius by antisense peptide nucleic acids in vitro.

PubMed

Goh, Shan; Loeffler, Anette; Lloyd, David H; Nair, Sean P; Good, Liam

2015-11-11

Antibiotic resistance genes can be targeted by antisense agents, which can reduce their expression and thus restore cellular susceptibility to existing antibiotics. Antisense inhibitors can be gene and pathogen specific, or designed to inhibit a group of bacteria having conserved sequences within resistance genes. Here, we aimed to develop antisense peptide nucleic acids (PNAs) that could be used to effectively restore susceptibility to β-lactams in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP). Antisense PNAs specific for conserved regions of the mobilisable gene mecA, and the growth essential gene, ftsZ, were designed. Clinical MRSA and MRSP strains of high oxacillin resistance were treated with PNAs and assayed for reduction in colony forming units on oxacillin plates, reduction in target gene mRNA levels, and cell size. Anti-mecA PNA at 7.5 and 2.5 μM reduced mecA mRNA in MRSA and MRSP (p < 0.05). At these PNA concentrations, 66 % of MRSA and 92 % of MRSP cells were killed by oxacillin (p < 0.01). Anti-ftsZ PNA at 7.5 and 2.5 μM reduced ftsZ mRNA in MRSA and MRSP, respectively (p ≤ 0.05). At these PNA concentrations, 86 % of MRSA cells and 95 % of MRSP cells were killed by oxacillin (p < 0.05). Anti-ftsZ PNAs resulted in swelling of bacterial cells. Scrambled PNA controls did not affect MRSA but sensitized MRSP moderately to oxacillin without affecting mRNA levels. The antisense PNAs effects observed provide in vitro proof of concept that this approach can be used to reverse β-lactam resistance in staphylococci. Further studies are warranted as clinical treatment alternatives are needed.

Linezolid resistant Staphylococcus haemolyticus: first case report from India.

PubMed

Gupta, Varsha; Garg, Shivani; Jain, Ruby; Garg, Sudhir; Chander, Jagdish

2012-10-01

Linezolid is being increasingly used in the treatment of infections with gram-positive organisms especially methicillin resistant Staphylococcal isolates. Though resistance to this antimicrobial is emerging but it is extremely rare. Here we document first case of linezolid resistant Staphylococcus haemolyticus (S.haemolyticus) from India. This organism was isolated from pus oozing from a postsurgical site in 61 year old male hailing from an adjoining state of Haryana. Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Colonization of butchers with livestock-associated methicillin-resistant Staphylococcus aureus.

PubMed

Boost, M; Ho, J; Guardabassi, L; O'Donoghue, M

2013-12-01

Reports have documented colonization of swine in Europe, North America and more recently in China with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA). Contamination of pig farmers, veterinarians and abattoir workers with these strains has been observed. However, although contamination levels of 10% of retail pork were reported from the Netherlands and Canada, there are limited data of contamination rates of workers handling raw meat. We investigated the rates of MRSA contamination of local butchers working in wet markets, where recently slaughtered pigs are cut up. Nasal swabs collected from 300 pork butchers at markets throughout Hong Kong were enriched in brain heart infusion broth with 5% salt and cultured on MRSASelect(®) . Isolates were confirmed as Staphylococcus aureus and susceptibility testing performed. The presence of mecA was confirmed, SCCmec and spa type determined and relatedness investigated by PFGE. Subjects completed a questionnaire on MRSA carriage risk factors. Seventeen samples (5.6%) yielded MRSA, 15 harbouring SCCmec IVb. Ten strains were t899 (CC9), previously reported from local pig carcasses. Five strains were healthcare associated: SCCmec type II, t701(CC6), colonizing two subjects at the same establishment, and single isolates of t008 (CC8), t002 (CC5) and t123 (CC45). The remaining isolates were t359 (CC97), previously reported from buffaloes, and t375 (CC5), reported from bovine milk. None of these butchers reported recent hospitalization or a healthcare worker in the family. Two had recently received antibiotics, one for a skin infection. Four reported wound infections within the last year. All were exposed to meat for >9 h per day. Carriage of MRSA was higher in butchers than in the general community. Although five strains were probably of healthcare origin, the high incidence of t899 (CC9) suggests that cross-contamination from pork occurs frequently. Washing of hands after touching raw pork is advised

An investigation of exudative epidermitis (greasy pig disease) and antimicrobial resistance patterns of Staphylococcus hyicus and Staphylococcus aureus isolated from clinical cases

PubMed Central

Park, Jeonghwa; Friendship, Robert M.; Poljak, Zvonimir; Weese, J. Scott; Dewey, Cate E.

2013-01-01

Exudative epidermitis (EE) is a common skin disease of young pigs, caused mainly by Staphylococcus hyicus. Increased prevalence of EE and poor response to treatment are reported. Common strategies used by Ontario pork producers to treat pigs with EE were determined using a survey. Injection of penicillin G was reported as the most common parenteral antibiotic choice. Antimicrobial resistance patterns of S. hyicus and Staphylococcus aureus isolated from clinical cases (30 herds with samples from approximately 6 pigs per farm) showed that 97% of S. hyicus isolates were resistant to penicillin G and ampicillin; 71% of these isolates were resistant to ceftiofur. Similar resistance was noted among S. aureus isolates. Antimicrobial resistance has become a problem in the treatment of EE in Ontario. PMID:23904636

Comparison of the BD MAX MRSA XT to the Cepheid™ Xpert® MRSA assay for the molecular detection of methicillin-resistant Staphylococcus aureus from nasal swabs.

PubMed

Mehta, Sanjay R; Estrada, Jasmine; Ybarra, Juan; Fierer, Joshua

2017-04-01

Variation in MRSA genotypes may affect the sensitivity of molecular assays to detect this organism. We compared 2 commonly used screening assays, the Cepheid™ Xpert® MRSA and the BD MAX™ MRSA XT on consecutively obtained nasal swabs from 479 subjects. Specimens giving discordant results were subjected to additional microbiologic and molecular testing. Six hundred forty-two (97.6%) of the 658 test results were concordant. Of the 16 discordant results from 12 subjects, additional results suggested that 9 (60%) of the 15 MRSA XT assays were likely correct, and 6 (40%) of the 15 Xpert® assays were likely correct. One discordant result could not be resolved. A mecA dropout and novel mec right-extremity junction (MREJ) sites led to false-positive and negative results by Xpert®. While both assays performed well, continued vigilance is needed to monitor for Staphylococcus aureus with novel MREJ sites, mecA dropouts, and mecC, leading to inaccurate results in screening assays. Published by Elsevier Inc.

Does nasal congestion have a role in decreased resistance to regular CPAP usage?

PubMed

İriz, Ayşe; Düzlü, Mehmet; Köktürk, Oğuz; Kemaloğlu, Yusuf Kemal; Eravcı, Fakih Cihat; Zorlu, Mehmet Ekrem; Karamert, Recep

2017-11-01

Nasal obstruction is known to cause resistance to continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea syndrome (OSAS). In this paper, short- and long-term nasal congestion in OSAS patients receiving CPAP treatment were evaluated with acoustic rhinometry (AR). A total of 36 patients with moderate-to-severe OSAS, diagnosed with polysomnography were included in the study. Ten healthy subjects without OSAS constituted the control group. Pre-treatment nasal patency were measured with AR in all participants. 26 patients used the recommended CPAP treatment. Ten patients did not accept CPAP treatment. The AR test was repeated for all the subjects after 1 and 3 months except the 3rd month's measurements of the control group. There was no statistically significant difference between the initial minimum cross-sectional area (MCA) measurements of OSAS patients, using or not using CPAP, and the control group (P > 0.05). However, the first month MCA measurements of patients receiving CPAP were found to be significantly decreased compared with the initial values (P < 0.001). There was no significant change in the first and third months MCA values in the control group and patients who did not use CPAP (P > 0.05). No significant difference revealed in the 3rd month MCA measurements of the patients using CPAP compared with the initial values (P > 0.05). In this study, the increased nasal congestion, which is thought to be the cause of CPAP resistance, was objectively demonstrated in OSAS patients using CPAP. In addition, the nasal congestion developing at the first month was shown to disappear over time, supporting the opinion that patient compliance in CPAP treatment is expected to increase after regular device usage.

Methicillin-resistant Staphylococcus aureus--an overview.

PubMed

Eadon, H J; Pinney, R J

1991-12-01

Methicillin-resistant strains of Staphylococcus aureus (MRSA) cause life-threatening infections, but they are no more pathogenic than methicillin-sensitive strains. Difficulties occur because of incorrect or missed identification of MRSA, and hence inappropriate or ineffective treatment of infections. Therapeutic options are severely limited and the increasing spectrum of resistance in MRSA is worrying. However, new methods of detection and new agents for treatment are being developed in response to the challenge of MRSA. Whilst the organism is a problem and control measures are necessary to contain its spread, the outlook is not bleak. In the medium term, the development of new, effective anti-MRSA agents should prevent the threat of MRSA becoming any greater in the field of hospital infection control.

Methicillin-resistant Staphylococcus aureus from dental school clinic surfaces and students.

PubMed

Roberts, Marilyn C; Soge, Olusegun O; Horst, Jeremy A; Ly, Kiet A; Milgrom, Peter

2011-10-01

Methicillin-resistant Staphylococcus aureus (MRSA) isolated from frequently touched dental school clinic surfaces were compared with MRSA isolated nasal cultures of dental students. Sixty-one dental students and 95 environmental surfaces from 7 clinics were sampled using SANICULT (Starplex Scientific Inc, Etobicoke, Ontario, Canada) swabs. Antimicrobial susceptibility testing was performed, and pulsed-field gel electrophoresis analysis, the mecA gene, multilocus sequence type, and SCCmec type were determined by polymerase chain reaction and sequencing. Thirteen (21%) dental students and 8 (8.4%) surfaces were MRSA positive. Three MRSA strains were SCCmec type IV, whereas 3 were nontypeable isolates and Panton-Valentine leukocidin positive (PVL+), and none were USA300. One surface and 1 student isolate shared the same multilocus sequence type ST 8 and were 75% related. Two groups of students carried the same MRSA strains. The MRSA-positive samples were from 4 of 7 dental clinics. In addition, 21% of the dental students carried MRSA, which is > 10 times higher than the general public and twice as frequent as in other university students. This is the first study to characterize MRSA from dental clinic surfaces and dental students and suggests that both may be reservoirs for MRSA. Further studies are needed to verify this premise. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Prevalence and genetic mechanisms of antimicrobial resistance in Staphylococcus species: A multicentre report of the indian council of medical research antimicrobial resistance surveillance network.

PubMed

Rajkumar, Sunanda; Sistla, Sujatha; Manoharan, Meerabai; Sugumar, Madhan; Nagasundaram, Niveditha; Parija, Subhash Chandra; Ray, Pallab; Bakthavatchalam, Yamuna Devi; Veeraraghavan, Balaji; Kapil, Arti; Walia, Kamini; Ohri, V C

2017-01-01

Routine surveillance of antimicrobial resistance (AMR) is an essential component of measures aimed to tackle the growing threat of resistant microbes in public health. This study presents a 1-year multicentre report on AMR in Staphylococcus species as part of Indian Council of Medical Research-AMR surveillance network. Staphylococcus species was routinely collected in the nodal and regional centres of the network and antimicrobial susceptibility testing was performed against a panel of antimicrobials. Minimum inhibitory concentration (MIC) values of vancomycin (VAN), daptomycin, tigecycline and linezolid (LNZ) against selected methicillin-resistant Staphylococcus aureus(MRSA) isolates were determined by E-test and MIC creep, if any, was determined. Resistant genotypes were determined by polymerase chain reaction for those isolates showing phenotypic resistance. The prevalence of MRSA was found to be range from moderate (21%) to high (45%) among the centres with an overall prevalence of 37.3%. High prevalence of resistance was observed with commonly used antimicrobials such as ciprofloxacin and erythromycin in all the centres. Resistance to LNZ was not encountered except for a single case. Full-blown resistance to VAN in S. aureus was not observed; however, a few VAN-intermediate S. aureus isolates were documented. The most common species of coagulase negative staphylococci (CoNS) identified was Staphylococcus haemolyticus and Staphylococcus epidermidis. Resistance among CoNS was relatively higher than S. aureus. Most phenotypically resistant organisms possessed the corresponding resistance genes. There were localised differences in the prevalence of resistance between the centres. The efficacy of the anti-MRSA antimicrobials was very high; however, almost all these antimicrobials showed evidence of creeping MIC.

Prevalence and factors associated with wound colonization by Staphylococcus spp. and Staphylococcus aureus in hospitalized patients in inland northeastern Brazil: a cross-sectional study

PubMed Central

2014-01-01

Background Infections by Staphylococcus spp. are often associated with wounds, especially in hospitalized patients. Wounds may be the source of bacteria causing cross-contamination, and are a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) infection. The aim of this study was to investigate the prevalence of wound colonization by Staphylococcus spp., especially S. aureus and MRSA, in hospitalized patients, and to identify the factors associated with such colonization. Methods This cross-sectional study enrolled patients with wounds who were hospitalized in a remote and underdeveloped inland region of northeastern Brazil with extreme poverty. Samples were collected using sterile swabs with 0.85% saline solution, and coagulase-negative Staphylococcus spp., S. aureus, and MRSA were identified using standard laboratory procedures. Data regarding the sociodemographic characteristics, antibiotic use, and comorbidities of the patients were collected using the medical records and a questionnaire. Results A total of 125 wounds were analyzed. The patients had a mean age of 63.88 years and a mean 3.84 years of school education. Eighty-one wounds (64.80%) were colonized by Staphylococcus spp. Twenty-five wounds (20%) were colonized by S. aureus, 32% of which were colonized by MRSA. Wound colonization by Staphylococcus spp. was associated with pneumonia or other respiratory disease (p = 0.03). Wound colonization by S. aureus was associated with nasal colonization by S. aureus (p < 0.001), fewer days of prior antibiotic use (p = 0.04), admission to a medical ward (p = 0.02), and age >65 years (p = 0.05). Among patients with wound colonization by MRSA, 37.50% had a history of prior antibiotic use, 75% had two or more comorbidities, 25% had cancer or diabetes, 50% had cardiovascular disease, and 50% died. Conclusions Wounds can be the source of Staphylococcus spp. infection, and high proportions of wounds are colonized by S. aureus and MRSA. Nasal

Prevalence and factors associated with wound colonization by Staphylococcus spp. and Staphylococcus aureus in hospitalized patients in inland northeastern Brazil: a cross-sectional study.

PubMed

Almeida, Gilmara Celli Maia; dos Santos, Marquiony Marques; Lima, Nara Grazieli Martins; Cidral, Thiago André; Melo, Maria Celeste Nunes; Lima, Kenio Costa

2014-06-13

Infections by Staphylococcus spp. are often associated with wounds, especially in hospitalized patients. Wounds may be the source of bacteria causing cross-contamination, and are a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) infection. The aim of this study was to investigate the prevalence of wound colonization by Staphylococcus spp., especially S. aureus and MRSA, in hospitalized patients, and to identify the factors associated with such colonization. This cross-sectional study enrolled patients with wounds who were hospitalized in a remote and underdeveloped inland region of northeastern Brazil with extreme poverty. Samples were collected using sterile swabs with 0.85% saline solution, and coagulase-negative Staphylococcus spp., S. aureus, and MRSA were identified using standard laboratory procedures. Data regarding the sociodemographic characteristics, antibiotic use, and comorbidities of the patients were collected using the medical records and a questionnaire. A total of 125 wounds were analyzed. The patients had a mean age of 63.88 years and a mean 3.84 years of school education. Eighty-one wounds (64.80%) were colonized by Staphylococcus spp. Twenty-five wounds (20%) were colonized by S. aureus, 32% of which were colonized by MRSA. Wound colonization by Staphylococcus spp. was associated with pneumonia or other respiratory disease (p = 0.03). Wound colonization by S. aureus was associated with nasal colonization by S. aureus (p < 0.001), fewer days of prior antibiotic use (p = 0.04), admission to a medical ward (p = 0.02), and age >65 years (p = 0.05). Among patients with wound colonization by MRSA, 37.50% had a history of prior antibiotic use, 75% had two or more comorbidities, 25% had cancer or diabetes, 50% had cardiovascular disease, and 50% died. Wounds can be the source of Staphylococcus spp. infection, and high proportions of wounds are colonized by S. aureus and MRSA. Nasal colonization by S. aureus may be a source for wound

Identification of ABC transporter genes conferring combined pleuromutilin-lincosamide-streptogramin A resistance in bovine methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci.

PubMed

Wendlandt, Sarah; Kadlec, Kristina; Feßler, Andrea T; Schwarz, Stefan

2015-06-12

The aim of this study was to investigate the genetic basis of combined pleuromutilin-lincosamide-streptogramin A resistance in 26 unrelated methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS) from dairy cows suffering from mastitis. The 26 pleuromutilin-resistant staphylococcal isolates were screened for the presence of the genes vga(A), vga(B), vga(C), vga(E), vga(E) variant, sal(A), vmlR, cfr, lsa(A), lsa(B), lsa(C), and lsa(E) by PCR. None of the 26 isolates carried the genes vga(B), vga(C), vga(E), vga(E) variant, vmlR, cfr, lsa(A), lsa(B), or lsa(C). Two Staphylococcus haemolyticus and single Staphylococcus xylosus, Staphylococcus lentus, and Staphylococcus hominis were vga(A)-positive. Twelve S. aureus, two Staphylococcus warneri, as well as single S. lentus and S. xylosus carried the lsa(E) gene. Moreover, single S. aureus, S. haemolyticus, S. xylosus, and Staphylococcus epidermidis were positive for both genes, vga(A) and lsa(E). The sal(A) gene was found in a single Staphylococcus sciuri. All ABC transporter genes were located in the chromosomal DNA, except for a plasmid-borne vga(A) gene in the S. epidermidis isolate. The genetic environment of the lsa(E)-positive isolates was analyzed using previously described PCR assays. Except for the S. warneri and S. xylosus, all lsa(E)-positive isolates harbored a part of the previously described enterococcal multiresistance gene cluster. This is the first report of the novel lsa(E) gene in the aforementioned bovine CoNS species. This is also the first identification of the sal(A) gene in a S. sciuri from a case of bovine mastitis. Moreover, the sal(A) gene was shown to also confer pleuromutilin resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Carriage of methicillin-resistant Staphylococcus aureus by veterinarians in Australia.

PubMed

Jordan, D; Simon, J; Fury, S; Moss, S; Giffard, P; Maiwald, M; Southwell, P; Barton, M D; Axon, J E; Morris, S G; Trott, D J

2011-05-01

To estimate the prevalence of carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Australian veterinarians. Individuals attending veterinary conferences in Australia in 2009 were recruited to provide nasal swabs and complete a questionnaire about their professional activities. Swabs were processed by standard methods for detecting MRSA and questionnaire responses were used to group veterinarians according to their areas of major work emphasis (species and practice type). Prevalence was estimated for each of these grouping and contingency tables and regression tree analysis used to explain the variation in MRSA carriage. Among the 771 respondents 'industry and government veterinarians' (controls) had the lowest prevalence of MRSA carriage at 0.9%. Veterinarians with horses as a major area of work emphasis had a prevalence of 11.8% (13-fold that of controls) and those whose only major emphasis was horses had a prevalence of 21.4% (23-fold that of controls). Veterinarians with dogs and cats as a major activity had a 4.9% prevalence (5-fold that of controls). Prevalence rates for other major activities (pigs, dairy and beef cattle, avian and wildlife) were also increased, but were estimated from smaller numbers of respondents. Regression tree analysis clearly isolated equine veterinarians and dog and cat practitioners as groups at increased risk of carriage of MRSA. Carriage of MRSA is a notable occupational health issue for veterinarians in clinical practice in Australia, particularly those who work with horses. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Pneumonia and New Methicillin-resistant Staphylococcus aureus Clone

PubMed Central

Tristan, Anne; François, Bruno; Etienne, Jerome; Delage-Corre, Manuella; Martin, Christian; Liassine, Nadia; Wannet, Wim; Denis, François; Ploy, Marie-Cécile

2006-01-01

Necrotizing pneumonia caused by Staphylococcus aureus strains carrying the Panton-Valentin leukocidin gene is a newly described disease entity. We report a new fatal case of necrotizing pneumonia. An S. aureus strain with an agr1 allele and of a new sequence type 377 was recovered, representing a new, emerging, community-acquired methicillin-resistant clone. PMID:16704793

Short communication: β-Lactam resistance and vancomycin heteroresistance in Staphylococcus spp. isolated from bovine subclinical mastitis.

PubMed

Mello, Priscila Luiza; Pinheiro, Luiza; Martins, Lisiane de Almeida; Brito, Maria Aparecida Vasconcelos Paiva; Ribeiro de Souza da Cunha, Maria de Lourdes

2017-08-01

The use of antimicrobial agents has led to the emergence of resistant bacterial strains over a relatively short period. Furthermore, Staphylococcus spp. can produce β-lactamase, which explains the survival of these strains in a focus of infection despite the use of a β-lactam antibiotic. The aim of this study was to evaluate the resistance of Staphylococcus spp. isolated from bovine subclinical mastitis to oxacillin and vancomycin (by minimum inhibitory concentration) and to detect vancomycin heteroresistance by a screening method. We also evaluated β-lactamase production and resistance due to hyperproduction of this enzyme and investigated the mecA and mecC genes and performed staphylococcal cassette chromosome mec typing. For this purpose, 181 Staphylococcus spp. isolated from mastitis subclinical bovine were analyzed. Using the phenotypic method, 33 (18.2%) of Staphylococcus spp. were resistant to oxacillin. In contrast, all isolates were susceptible to vancomycin, and heteroresistance was detected by the screening method in 13 isolates. Production of β-lactamase was observed in 174 (96%) of the Staphylococcus spp. isolates. The mecA gene was detected in 8 isolates, all of them belonging to the species Staphylococcus epidermidis, and staphylococcal cassette chromosome mec typing revealed the presence of type I and type IV isolates. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Draft genome sequence of multidrug-resistant Staphylococcus haemolyticus IPK_TSA25 harbouring a Staphylococcus aureus plasmid, pS0385-1.

PubMed

Kim, Hyung Jun; Jang, Soojin

2017-12-01

Staphylococcus haemolyticus is the second most frequently isolated coagulase-negative staphylococci from blood cultures. Moreover, multidrug resistance associated with the genome flexibility of S. haemolyticus has been increasingly reported worldwide. Here we report the draft genome sequence of multidrug-resistant S. haemolyticus IPK_TSA25 isolated from a building surface in South Korea. Genomic DNA of S. haemolyticus IPK_TSA25 was sequenced using the PacBio RS II sequencing platform. Generated reads were assembled using PacBio SMRT Analysis 2.3.0. The draft genome was annotated and antibiotic resistance genes were identified. The genome of 2517398bp contains various antibiotic resistance genes associated with resistance to β-lactams, aminoglycosides and macrolides. Genome analysis also revealed chromosomal integration of the full-length Staphylococcus aureus plasmid pS0385-1 containing a tetracycline resistance gene. The genome sequence reported in this study will provide valuable information to understand the flexibility of the S. haemolyticus genome, which facilitates acquisition of antibiotic resistance genes and contributes to the dissemination of antibiotic resistance by this emerging pathogen. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Mobile phones and computer keyboards: unlikely reservoirs of multidrug-resistant organisms in the tertiary intensive care unit.

PubMed

Smibert, O C; Aung, A K; Woolnough, E; Carter, G P; Schultz, M B; Howden, B P; Seemann, T; Spelman, D; McGloughlin, S; Peleg, A Y

2018-03-02

Few studies have used molecular epidemiological methods to study transmission links to clinical isolates in intensive care units. Ninety-four multidrug-resistant organisms (MDROs) cultured from routine specimens from intensive care unit (ICU) patients over 13 weeks were stored (11 meticillin-resistant Staphylococcus aureus (MRSA), two vancomycin-resistant enterococci and 81 Gram-negative bacteria). Medical staff personal mobile phones, departmental phones, and ICU keyboards were swabbed and cultured for MDROs; MRSA was isolated from two phones. Environmental and patient isolates of the same genus were selected for whole genome sequencing. On whole genome sequencing, the mobile phone isolates had a pairwise single nucleotide polymorphism (SNP) distance of 183. However, >15,000 core genome SNPs separated the mobile phone and clinical isolates. In a low-endemic setting, mobile phones and keyboards appear unlikely to contribute to hospital-acquired MDROs. Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

21 CFR 874.3900 - Nasal dilator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nasal dilator. 874.3900 Section 874.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... nasal airflow. The device decreases airway resistance and increases nasal airflow. The external nasal...

21 CFR 874.3900 - Nasal dilator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nasal dilator. 874.3900 Section 874.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... nasal airflow. The device decreases airway resistance and increases nasal airflow. The external nasal...

Toxic Shock Syndrome Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) After Expander-Based Breast Reconstruction.

PubMed

Suga, Hirotaka; Shiraishi, Tomohiro; Takushima, Akihiko; Harii, Kiyonori

2016-01-01

Toxic shock syndrome is a rare but life-threatening complication after plastic surgery procedures. We experienced 2 cases of toxic shock syndrome after expander-based breast reconstruction caused by methicillin-resistant Staphylococcus aureus. The first patient took a severe clinical course due to the delayed diagnosis and treatment, and the second patient recovered rapidly after the early diagnosis and treatment based on our experience of the first case. Fever, rash, and gastrointestinal symptoms (diarrhea and/or vomiting) were characteristic and important for the early diagnosis of toxic shock syndrome. Considering the increased prevalence of methicillin-resistant Staphylococcus aureus, we should suspect methicillin-resistant Staphylococcus aureus in cases of toxic shock syndrome that occur postoperatively, and the empiric administration of vancomycin should be initiated in such cases.

Linezolid-resistant mucoid Staphylococcus haemolyticus from a tertiary-care centre in Delhi.

PubMed

Matlani, M; Shende, T; Bhandari, V; Dawar, R; Sardana, R; Gaind, R

2016-05-01

We report an unusual morphological mucoid variant of Staphylococcus haemolyticus associated with linezolid resistance from a patient with sepsis. Linezolid resistance and mucoid character together made this pathogen difficult to treat. To our knowledge this is the first such report.

Performance of CHROMagar MRSA Medium for Detection of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Diederen, Bram; van Duijn, Inge; van Belkum, Alex; Willemse, Piet; van Keulen, Peter; Kluytmans, Jan

2005-01-01

CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h. PMID:15815020

A Survey of Staphylococcus sp and its Methicillin Resistance aboard the International Space Station

NASA Technical Reports Server (NTRS)

Bassinger, V. J.; Fontenot, S. L.; Castro, V. A.; Ott, C.; Healy, M.; Pierson, D. L.

2004-01-01

Background: Within the past few years, methicillin-resistant Staphylococcus aureus has emerged in environments with susceptible hosts in close proximity, such as hospitals and nursing homes. As the International Space Station (ISS) represents a semi-closed environment with a high level of crewmember interaction, an evaluation of isolates of clinical and environmental Staphylococcus aureus and coagulase negative Staphylococcus was performed to determine if this trend was also present in astronauts occupying ISS or on surfaces of the space station itself. Methods: Identification of isolates was completed using VITEK (GPI cards, BioMerieux), 16S ribosomal DNA analysis (MicroSeq 500, ABI), and Rep-PCR DNA fingerprinting (Divemilab, Bacterial Barcodes). Susceptibility tests were performed using VITEK (GPS-105 cards, BioMerieux) and resistance characteristics were evaluated by testing for the presence of the mecA gene (PBP2' MRSA test kit, Oxoid). Results: Rep-PCR analysis indicated the transfer of S. aureus between crewmembers and between crewmembers and ISS surfaces. While a variety of S. aureus were identified from both the crewmembers and environment, evaluations of the microbial population indicated minimal methicillin resistance. Results of this study indicated that within the semi-closed ISS environment, transfer of bacteria between crewmembers and their environment has been occurring, although there was no indication of a high concentration of methicillin resistant Staphylococcus species. Conclusions: While this study suggests that the spread of methicillin resistant S. aureus is not currently a concern aboard ISS, the increasing incidence of Earth-based antibiotic resistance indicates a need for continued clinical and environmental monitoring.

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis.

PubMed

Kumar, Vasudevan Anil; Nair, Nisha; Thachathodiyl, Rajesh; Nandakumar, Aswathy; Dinesh, Kavitha R; Thatcher, Eileen; Karim, Shamsul; Biswas, Raja

2013-07-01

Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.

Molecular characterization of methicillin-resistant Staphylococcus aureus strains from pet animals and veterinary staff in China.

PubMed

Zhang, Wanjiang; Hao, Zhihui; Wang, Yang; Cao, Xingyuan; Logue, Catherine M; Wang, Bing; Yang, Jing; Shen, Jianzhong; Wu, Congming

2011-11-01

The aim of this study was to determine the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates from pet animals and veterinary staff and the characteristics of these isolates. A total of 22 MRSA isolates were isolated from nasal swabs from dogs, cats and veterinary staff in six pet hospitals in six cities, and examined for antimicrobial susceptibility, the presence of resistance genes, Panton-Valentine leukocidin gene lukF-lukS, staphylococcal chromosomal cassette (SCC) mec typing, spa tying, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Of 22 MRSA isolates, 21 were recovered from pet animals, and one was isolated from a member of sstaff. All 22 MRSA strains were resistant to penicillin, oxacillin, azithromycin, clindamycin and ceftriaxone, and harboured mecA, ermB and linA genes. The lukF-lukS gene was not detected in any of the MRSA isolates. Eighteen MRSA strains from Qingdao belonged to ST59-MRSA-IV-spa t437. Of four MRSA isolates from Beijing, one belonged to ST398-MRSA-V-spa t034, and three belonged to ST239-MRSA-III-spa t030 profiles. Two PFGE types (A and B) were identified. Two isolates originating from dogs and one isolate originating from a staff member in Beijing shared similar PFGE patterns. Our cumulative data suggested that cross-transmission of MRSA may have occurred between pet animals and veterinary staff. Copyright © 2011 Elsevier Ltd. All rights reserved.

Methicillin-resistant Staphylococcus aureus colonization of house officers.

PubMed

Barbosa, Anna A; Chapin, Kim; Mermel, Leonard A

2009-09-01

We performed a prospective prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in the nares of 50 medical and 50 surgical house officers. None of the 50 internal medicine house officers and 5 of the 50 general surgery house officers had MRSA nares colonization (P = .03). None of the MRSA isolates recovered from the surgical house officers were identical.

Coagulase-positive Staphylococcus isolated from wildlife: Identification, molecular characterization and evaluation of resistance profiles with focus on a methicillin-resistant strain.

PubMed

Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Gnat, Sebastian; Wojtanowicz-Markiewicz, Katarzyna; Trościańczyk, Aleksandra

2016-02-01

The aim of the study was molecular analysis of coagulase-positive isolates of Staphylococcus bacteria obtained from wild animals and evaluation of their resistance to antimicrobial agents. A total of 76 rectal swabs were taken from wild animals. The species of the Staphylococcus isolates was determined by MALDI TOF MS, susceptibility to antimicrobials was evaluated by phenotypic and molecular methods, epidemiological analysis (ADSRRS-fingerprinting) was also carried out. MRSA isolate was typed by MLST and spa-typing. The animals tested, were carriers (n=38) of coagulase-positive Staphylococcus (S. aureus, S. pseudintermedius and S. delphini B). Analyzed isolates were resistant to 1 or 2 antimicrobials, which was confirmed by the presence of genes (blaZ, ermA, ermB, msrA, tetK and tetM). A multi-drug resistant and methicillin-resistant isolate of S. aureus was obtained as well (MRSA, ST8, t1635, PVL-positive and ACME-negative). The ADSRRS-fingerprinting method enabled interspecific and intraspecific differentiation of coagulase-positive Staphylococcus isolates, revealing a certain degree of correlation between the species of the isolate, and the degree of similarity between the isolates. The presence of resistance genes in 13% (5/38) of the isolates obtained from wild animals, including one methicillin-resistant isolate, is relatively small in comparison to the degree of colonization by resistant strains in humans, livestock or pets. Nevertheless, due to the possibility of contact between wild animals, domestic animals and humans, transmission of resistant strains is possible, as suggested by our isolation of a MRSA strain typed as ST8 and specific spa type t1635, which had previously been isolated exclusively from humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genetic Mimetics of Mycobacterium tuberculosis and Methicillin-Resistant Staphylococcus aureus as Verification Standards for Molecular Diagnostics.

PubMed

Machowski, Edith Erika; Kana, Bavesh Davandra

2017-12-01

Molecular diagnostics have revolutionized the management of health care through enhanced detection of disease or infection and effective enrollment into treatment. In recognition of this, the World Health Organization approved the rollout of nucleic acid amplification technologies for identification of Mycobacterium tuberculosis using platforms such as GeneXpert MTB/RIF, the GenoType MTBDR plus line probe assay, and, more recently, GeneXpert MTB/RIF Ultra. These assays can simultaneously detect tuberculosis infection and assess rifampin resistance. However, their widespread use in health systems requires verification and quality assurance programs. To enable development of these, we report the construction of genetically modified strains of Mycobacterium smegmatis that mimic the profile of Mycobacterium tuberculosis on both the GeneXpert MTB/RIF and the MTBDR plus line probe diagnostic tests. Using site-specific gene editing, we also created derivatives that faithfully mimic the diagnostic result of rifampin-resistant M. tuberculosis , with mutations at positions 513, 516, 526, 531, and 533 in the rifampin resistance-determining region of the rpoB gene. Next, we extended this approach to other diseases and demonstrated that a Staphylococcus aureus gene sequence can be introduced into M. smegmatis to generate a positive response for the SCC mec probe in the GeneXpert SA Nasal Complete molecular diagnostic cartridge, designed for identification of methicillin-resistant S. aureus These biomimetic strains are cost-effective, have low biohazard content, accurately mimic drug resistance, and can be produced with relative ease, thus illustrating their potential for widespread use as verification standards for diagnosis of a variety of diseases. Copyright © 2017 American Society for Microbiology.

Vancomycin-resistant Staphylococcus aureus (VRSA) in hepatic cirrhosis patient: a case report

NASA Astrophysics Data System (ADS)

Ramazoni, M.; Siregar, M. L.; Jamil, K. F.

2018-03-01

The irrational use of vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) infections result in the emergence of vancomycin-resistant Staphylococcus aureus (VRSA) pathogen, which can pose a threat to the world healthcare. A 32-year-old male with hepatic cirrhosis patient admitted with recurrent gastrointestinal bleeding with a wound in his left leg since 6 months ago; the result microbiological culture showed a VRSA with minimum inhibitory concentration (MIC) vancomycin ≥32μg/mL The patient was treated with trimethoprim/sulfamethoxazole combination according to cultural sensitivity. The second microbiological culture showed thesame result. VRSA is a rare and difficult condition to handle. The success of therapy for this VRSA case warn us how important to cut the S. aureus distribution chain with a high level of resistance.

Rapid Detection of Methicillin-Resistant Staphylococcus aureus Isolates by Turanose Fermentation Method

PubMed Central

Raeisi, Javad; Saifi, Mahnaz; Pourshafie, Mohammad Reza; Asadi Karam, Mohammad Reza; Mohajerani, Hamid Reza

2015-01-01

Background: Methicillin-Resistant Staphylococcus aureus (MRSA) is a major pathogen in the hospital and community settings. Rapid methods to diagnose S. aureus infections are sought by many researchers worldwide. The current study aimed to utilize a phenotypic method of turanose fermentation to identify methicillin-susceptible and resistant S. aureus. Objectives: The current study aimed to assay the turanose metabolism at different dilutions as a rapid phenotypic method to identify MRSA isolates. Materials and Methods: A total of 150 Staphylococcus isolates were collected from Tehran health centers. Staphylococcus aureus isolates were identified based on cultural characteristics, biochemical reactions and positive tube coagulase test. Methicillin resistance was determined by the disk diffusion method. The Polymerase Chain Reaction amplification was used to detect the mecA gene in MRSA isolates. All the methicillin-resistant and susceptible isolates were evaluated for turanose metabolism with 1%, 0.7% and 0.5% dilutions using the microplate method. Results: Out of the 150 staphylococcal isolates, 80 were identified as S. aureus. Among which 40 (50%) of the isolates were MRSA. The mecA gene was present in all S. aureus isolates resistant to methicillin. A considerable difference was also observed between susceptible and resistant isolates of S. aureus at a 0.7% dilution of turanose. Conclusions: Since it is highly important to rapidly detect MRSA isolates, especially in nosocomial infections, phenotypic methods may certainly be useful for this purpose. Resistance to methicillin in S. aureus shows a substantially increased ability in turanose metabolism. It is concluded that fermentation of turanose at 0.7% dilution could be a rapid detection method for primary screening of MRSA isolates. PMID:26495105

Antibiotic Resistant and Virulence Determinants of Staphylococcus haemolyticus C10A as Revealed by Whole Genome Sequencing.

PubMed

Chan, Kok-Gan; Ng, Kim Tien; Chong, Teik Min; Pang, Yong Kek; Kamarulzaman, Adeeba; Yin, Wai-Fong; Tee, Kok Keng

2015-01-01

Staphylococcus haemolyticus is one of the pathogens that harbor a high level of antibiotic resistance. Here, we highlighted the potential determinants for multidrug resistance and virulence from the draft genome of Staphylococcus haemolyticus strain C10A, isolated from a patient with chronic obstructive pulmonary disease exacerbation.

Human-to-Dog Transmission of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Wolfhagen, Maurice J.H.M.; Heck, Max E.O.C.; Wannet, Wim J.B.; Fluit, Ad C.

2004-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) was cultured from the nose of a healthy dog whose owner was colonized with MRSA while she worked in a Dutch nursing home. Pulsed-field gel electrophoresis and typing of the staphylococcal chromosome cassette mec (SCCmec) region showed that both MRSA strains were identical. PMID:15663871

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging cause of acute bacterial parotitis.

PubMed

Nicolasora, Nelson P; Zacharek, Mark A; Malani, Anurag N

2009-02-01

Staphylococcus aureus has long been recognized as a cause of acute bacterial parotitis. A case of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) parotitis is presented, highlighting the emergence of this increasingly important pathogen to cause a wide variety of infections. Also reviewed are the salient clinical and microbiologic features of this novel infection.

Molecular Types of Methicillin-Resistant Staphylococcus aureus and Methicillin-Sensitive S. aureus Strains Causing Skin and Soft Tissue Infections and Nasal Colonization, Identified in Community Health Centers in New York City

PubMed Central

Pardos de la Gandara, Maria; Raygoza Garay, Juan Antonio; Mwangi, Michael; Tobin, Jonathan N.; Tsang, Amanda; Khalida, Chamanara; D'Orazio, Brianna; Kost, Rhonda G.; Leinberger-Jabari, Andrea; Coffran, Cameron; Evering, Teresa H.; Coller, Barry S.; Balachandra, Shirish; Urban, Tracie; Parola, Claude; Salvato, Scott; Jenks, Nancy; Wu, Daren; Burgess, Rhonda; Chung, Marilyn; de Lencastre, Herminia

2015-01-01

In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureus strains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureus were collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus (MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus (MSSA) was recovered from 24. Most—46 of the 63–wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL+) group of S. aureus clone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureus infections, 30 were also colonized by S. aureus in the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing. PMID:26063853

Survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in healthy college students, Hawai'i.

PubMed

Morita, Jennifer E; Fujioka, Roger S; Tice, Alan D; Berestecky, John; Sato, Dayna; Seifried, Steven E; Katz, Alan R

2007-08-01

Currently, the carriage rate for Community-Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) is unknown in Hawai'i. This survey focuses on a healthy population of 95 college students and 5 faculty who completed a survey related to possible risk factors for colonization of Staphylococcus aureus and were sampled for S. aureus from their anterior nares. Thirty-three (33%) subjects were carrying Staphylococcus aureus and of those, 3 (3%) carried MRSA. There was no significant association between Staphylococcus aureus carriage and ethnicity, gender exposure to seawater, prior Staphylococcus aureus infections, recent antibiotic use, or pets. Additional testing of a larger group of healthy individuals would be beneficial in assessing factors associated with CA-MRSA and Methicillin-susceptible Staphylococcus aureus (MSSA) carriage in Hawai'i.

Tolerability of a probiotic in subjects with a history of methicillin-resistant Staphylococcus aureus colonisation.

PubMed

Warrack, S; Panjikar, P; Duster, M; Safdar, N

2014-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of major public health importance. Colonisation precedes infection; thus reducing MRSA carriage may be of benefit for reducing infection. Probiotics represent a novel approach to reducing MRSA carriage. We undertook a pilot feasibility randomised controlled trial of the tolerability and acceptability of probiotics for reducing nasal and intestinal carriage of MRSA. In addition, subjects were screened for vancomycin-resistant enterocococci (VRE). Subjects with a history of MRSA were recruited from a large, academic medical center and randomised to take either a placebo or probiotic (Lactobacillus rhamnosus HN001). Subjects returned to the clinic after four weeks for further testing to determine adherence to the probiotic regimen and colonisation of MRSA. 48 subjects were enrolled and randomised. Nearly 25% were transplant recipients and 30% had diabetes. The probiotic was well tolerated in the study population though minor side effects, such as nausea and bloating, were observed. A majority of the subjects randomised to HN001 had good adherence to the regimen. At the four week time point among subjects randomised to the probiotic, MRSA was detected in 67 and 50% of subjects colonised in the nares and the gastrointestinal tract, respectively. Three subjects who initially tested positive for VRE were negative after four weeks of probiotic exposure. Probiotics were well tolerated in our study population of largely immunocompromised subjects with multiple comorbidities. Adherence to the intervention was good. Probiotics should be studied further for their potential to reduce colonisation by multidrug resistant bacteria.

Methicillin-resistant Staphylococcus aureus in pigs and farm workers on conventional and antibiotic-free swine farms in the USA.

PubMed

Smith, Tara C; Gebreyes, Wondwossen A; Abley, Melanie J; Harper, Abby L; Forshey, Brett M; Male, Michael J; Martin, H Wayne; Molla, Bayleyegn Z; Sreevatsan, Srinand; Thakur, Siddhartha; Thiruvengadam, Madhumathi; Davies, Peter R

2013-01-01

Much uncertainty remains about the origin and public health implications of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA). This study aimed to investigate the occurrence and prevalence of MRSA in general and LA-MRSA in particular in pigs and farm workers in five states. We collected nasal swabs from pigs and farm workers at 45 swine herds (21 antibiotic-free herds; 24 conventional herds) in Illinois, Iowa, Minnesota, North Carolina and Ohio. MRSA was isolated from 50 of 1085 pigs (4.6%) and 31 of 148 (20.9%) of farm workers. MRSA-positive pigs and people were clustered in four conventional swine farms in Iowa and Illinois. Based on genotyping, spa type t034, a common livestock associated variant, was predominant among both human and swine isolates. These results confirm the presence of LA-MRSA in pigs and swine farm workers in the USA, but the prevalence found is relatively low compared with European studies.

[Molecular study of methicillin-resistant Staphylococcus haemolyticus in a Mexican hospital].

PubMed

Castro, Natividad; Loaiza-Loeza, María Salomé; Calderón-Navarro, Amparo; Sánchez, Alejandro; Silva-Sánchez, Jesús

2006-01-01

To perform the molecular characterization of methicillin-resistant Staphylococcus haemolyticus (MRSH) clinical isolates from patients in a Mexican hospital. Sixty three Staphylococcus ssp. isolates collected from September 2000 to October 2002 were analyzed. Antimicrobial susceptibility was determined by disk diffusion method and the presence of the mecA gene was detected by PCR technique. Isolates characterization was carried out by pulsed field gel electrophoresis (PFGE). The frequency of S. haemolyticus was 25.5% (18 of 63 clinical isolates), all S. haemolyticus isolates were methicillin-resistant and they were positive for the mecA gene. A major pattern (A) with 8 subtypes was identified. This clone was distributed during the 20 months period. Most of them were isolated from the surgery (55%) and pediatric services (27.5%). The methicillin-resistant S. haemolyticus permanence as pathogen in this hospital, suggest the implementation of control programs in order to decrease the prevalence of this multiresistant pathogen.

Mechanisms of antibiotic resistance in Staphylococcus aureus.

PubMed

Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

2007-06-01

Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

Scarlet fever caused by community-associated methicillin-resistant Staphylococcus aureus.

PubMed

Lu, Ying-Chun; Chen, Shyi-Jou; Lo, Wen-Tsung

2011-07-01

We describe a previously healthy 2.5-year-old boy with staphylococcal scarlet fever associated with acute suppurative otitis media due to community-associated methicillin-resistant Staphylococcus aureus. The patient was successfully treated by spontaneous drainage in combination with trimethoprim-sulfamethoxazole therapy.

Antimicrobial resistance patterns of Staphylococcus species isolated from cats presented at a veterinary academic hospital in South Africa.

PubMed

Qekwana, Daniel Nenene; Sebola, Dikeledi; Oguttu, James Wabwire; Odoi, Agricola

2017-09-15

Antimicrobial resistance is becoming increasingly important in both human and veterinary medicine. This study investigated the proportion of antimicrobial resistant samples and resistance patterns of Staphylococcus isolates from cats presented at a veterinary teaching hospital in South Africa. Records of 216 samples from cats that were submitted to the bacteriology laboratory of the University of Pretoria academic veterinary hospital between 2007 and 2012 were evaluated. Isolates were subjected to antimicrobial susceptibility testing against a panel of 15 drugs using the disc diffusion method. Chi square and Fisher's exact tests were used to assess simple associations between antimicrobial resistance and age group, sex, breed and specimen type. Additionally, associations between Staphylococcus infection and age group, breed, sex and specimen type were assessed using logistic regression. Staphylococcus spp. isolates were identified in 17.6% (38/216) of the samples submitted and 4.6% (10/216) of these were unspeciated. The majority (61.1%,11/18) of the isolates were from skin samples, followed by otitis media (34.5%, 10/29). Coagulase Positive Staphylococcus (CoPS) comprised 11.1% (24/216) of the samples of which 7.9% (17/216) were S. intermedius group and 3.2% (7/216) were S. aureus. Among the Coagulase Negative Staphylococcus (CoNS) (1.9%, 4/216), S. felis and S. simulans each constituted 0.9% (2/216). There was a significant association between Staphylococcus spp. infection and specimen type with odds of infection being higher for ear canal and skin compared to urine specimens. There were higher proportions of samples resistant to clindamycin 34.2% (13/25), ampicillin 32.4% (2/26), lincospectin 31.6% (12/26) and penicillin-G 29.0% (11/27). Sixty three percent (24/38) of Staphylococcus spp. were resistant to one antimicrobial agent and 15.8% were multidrug resistant (MDR). MDR was more common among S. aureus 28.6% (2/7) than S. intermedius group isolates 11.8% (2

Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Wang, Yucheng; Dai, Tianhong; Gu, Ying

2016-10-01

Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

Methicillin-resistant Staphylococcus aureus: an overview for manual therapists().

PubMed

Green, Bart N; Johnson, Claire D; Egan, Jonathon Todd; Rosenthal, Michael; Griffith, Erin A; Evans, Marion Willard

2012-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with difficult-to-treat infections and high levels of morbidity. Manual practitioners work in environments where MRSA is a common acquired infection. The purpose of this review is to provide a practical overview of MRSA as it applies to the manual therapy professions (eg, physical and occupational therapy, athletic training, chiropractic, osteopathy, massage, sports medicine) and to discuss how to identify and prevent MRSA infections in manual therapy work environments. PubMed and CINAHL were searched from the beginning of their respective indexing years through June 2011 using the search terms MRSA, methicillin-resistant Staphylococcus aureus, and Staphylococcus aureus. Texts and authoritative Web sites were also reviewed. Pertinent articles from the authors' libraries were included if they were not already identified in the literature search. Articles were included if they were applicable to ambulatory health care environments in which manual therapists work or if the content of the article related to the clinical management of MRSA. Following information extraction, 95 citations were included in this review, to include 76 peer-reviewed journal articles, 16 government Web sites, and 3 textbooks. Information was organized into 10 clinically relevant categories for presentation. Information was organized into the following clinically relevant categories: microbiology, development of MRSA, risk factors for infection, clinical presentation, diagnostic tests, screening tests, reporting, treatment, prevention for patients and athletes, and prevention for health care workers. Methicillin-resistant S aureus is a health risk in the community and to patients and athletes treated by manual therapists. Manual practitioners can play an essential role in recognizing MRSA infections and helping to control its transmission in the health care environment and the community. Essential methods for protecting patients

Carriage of methicillin-resistant Staphylococcus aureus by healthy companion animals

USDA-ARS?s Scientific Manuscript database

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant human pathogen and has also been associated with wounded or ill companion animals. Healthy animals may also harbor MRSA without presenting any symptoms, but little is known about the prevalence of MRSA among these animals. Therefo...

Role of the Stringent Stress Response in the Antibiotic Resistance Phenotype of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Aedo, Sandra

2016-01-01

Resistance to beta-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA) requires the presence of an acquired genetic determinant, mecA or mecC, which encode penicillin-binding protein PBP2A or PBP2A′, respectively. Although all MRSA strains share a mechanism of resistance, the phenotypic expression of beta-lactam resistance shows considerable strain-to-strain variation. The stringent stress response, a stress response that results from nutrient limitation, was shown to play a key role in determining the resistance level of an MRSA strain. In the present study, we validated the impact of the stringent stress response on transcription and translation of mecA in the MRSA clinical isolate strain N315, which also carries known regulatory genes (mecI/mecR1/mecR2 and blaI/blaR1) for mecA transcription. We showed that the impact of the stringent stress response on the resistance level may be restricted to beta-lactam resistance based on a “foreign” determinant such as mecA, as opposed to resistance based on mutations in the native S. aureus determinant pbpB (encoding PBP2). Our observations demonstrate that high-level resistance mediated by the stringent stress response follows the current model of beta-lactam resistance in which the native PBP2 protein is also essential for expression of the resistance phenotype. We also show that the Staphylococcus sciuri pbpD gene (also called mecAI), the putative evolutionary precursor of mecA, confers oxacillin resistance in an S. aureus strain, generating a heterogeneous phenotype that can be converted to high and homogenous resistance by induction of the stringent stress response in the bacteria. PMID:26833147

Methicillin-Resistant "Staphylococcus aureus" on Campus: A New Challenge to College Health

ERIC Educational Resources Information Center

Weiner, H. Richard

2008-01-01

As new drugs to control bacterial pathogens are developed, the organisms evolve to survive. "Staphylococcus aureus", a common organism, has steadily developed resistance to antibiotics. For more than 40 years, resistant "S. aureus" presented a formidable problem to hospitalized patients; in the past decade, however, it has begun to appear outside…

Methicillin-resistant Staphylococcus aureus survival on hospital fomites.

PubMed

Huang, Robert; Mehta, Sanjay; Weed, Diane; Price, Connie Savor

2006-11-01

We examined the duration of survival of 2 strains of methicillin-resistant Staphylococcus aureus (MRSA) on 3 types of hospital fomites. MRSA survived for 11 days on a plastic patient chart, more than 12 days on a laminated tabletop, and 9 days on a cloth curtain. Irregular surfaces may help harbor organisms in the environment. In addition to contact precautions, MRSA containment during an outbreak should include concurrent environmental decontamination.

Zinc resistance within swine associated methicillin resistant Staphylococcus aureus (MRSA) isolates in the USA is associated with MLST lineage

USDA-ARS?s Scientific Manuscript database

Zinc resistance in livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) is mediated by the czrC gene co-located with the mecA gene, encoding methicillin resistance, on the type V SCCmec element. Since the czrC gene and the mecA gene are co-located on the SCCmec element, it has ...

An outbreak of infections caused by strains of Staphylococcus aureus resistant to methicillin and aminoglycosides. II. Epidemiologic studies.

PubMed

Crossley, K; Landesman, B; Zaske, D

1979-03-01

Studies to determine the epidemiologic behavior of strains of Staphylococcus aureus resistant to methicillin and aminoglycosides (MARS) were conducted over a period of two and one-half years, during which MARS were isolated from 201 patients at a hospital in the midwestern United States. Most cases of infection or colonization with MARS (156 of 201) occurred in patients with burns. In the burn unit, MARS were recovered from the air, from the hair and hands of personnel, and from inanimate objects. Nasal (72%) and rectal (66%) colonization were common among burned patients with infected or colonized burn wounds but occurred in only six of 74 burn unit personnel. When compared with two control periods, the prophylactic use of antistaphylococcal agents in patients with burns increased markedly at the time the outbreak began. Of the 45 patients without burns from whom MARS were isolated, 42 (93%) were surgical patients. MARS were not demonstrated in the air or environment of patients with infected surgical wounds. None of 334 non-burn unit hospital personnel were found to be carriers of MARS. Four phage types (83A, 6/75/85, 29/52/80, and 92) were recovered during the outbreak. A determinant of antibiotic resistance was probably transmitted among strains of S. aureus.

Livestock-associated Methicillin-Resistant Staphylococcus aureus in Humans, Europe

PubMed Central

Monnet, Dominique L.; Voss, Andreas; Krziwanek, Karina; Allerberger, Franz; Struelens, Marc; Zemlickova, Helena; Skov, Robert L.; Vuopio-Varkila, Jaana; Cuny, Christiane; Friedrich, Alexander W.; Spiliopoulou, Iris; Pászti, Judit; Hardardottir, Hjordis; Rossney, Angela; Pan, Angelo; Pantosti, Annalisa; Borg, Michael; Grundmann, Hajo; Mueller-Premru, Manica; Olsson-Liljequist, Barbro; Widmer, Andreas; Harbarth, Stephan; Schweiger, Alexander; Unal, Serhat; Kluytmans, Jan A.J.W.

2011-01-01

To estimate the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans that were sequence type (ST) 398, we surveyed 24 laboratories in 17 countries in Europe in 2007. Livestock-associated MRSA ST398 accounted for only a small proportion of MRSA isolates from humans; most were from the Netherlands, Belgium, Denmark, and Austria. PMID:21392444

Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

Beta-lactams against methicillin-resistant Staphylococcus aureus.

PubMed

Guignard, Bertrand; Entenza, José M; Moreillon, Philippe

2005-10-01

Methicillin-resistant Staphylococcus aureus (MRSA) have developed resistance to virtually all non-experimental antibiotics. They are intrinsically resistant to beta-lactams by virtue of newly acquired low-affinity penicillin-binding protein 2A (PBP2A). Because PBP2A can build the wall when other PBPs are blocked by beta-lactams, designing beta-lactams capable of blocking this additional target should help solve the issue. Older molecules including penicillin G, amoxicillin and ampicillin had relatively good PBP2A affinities, and successfully treated experimental endocarditis caused by MRSA, provided that the bacterial penicillinase could be inhibited. Newer anti-PBP2A beta-lactams with over 10-fold greater PBP2A affinities and low minimal inhibitory concentrations were developed, primarily in the cephem and carbapenem classes. They are also very resistant to penicillinase. Most have demonstrated anti-MRSA activity in animal models of infection, and two--the carbapenem CS-023 and the cephalosporin ceftopibrole medocaril--have proceeded to Phase II and Phase III clinical evaluation. Thus, clinically useful anti-MRSA beta-lactams are imminent.

Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

PubMed

Rehm, Susan J; Tice, Alan

2010-09-15

The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

Using the ultra-long pulse width pulsed dye laser and elliptical spot to treat resistant nasal telangiectasia.

PubMed

Madan, Vishal; Ferguson, Janice

2010-01-01

Thick linear telangiectasia on the ala nasi and nasolabial crease can be resistant to treatment with the potassium-titanyl-phosphate (KTP) laser and the traditional round spot on a pulsed dye laser (PDL). We evaluated the efficacy of a 3 mm x 10 mm elliptical spot using the ultra-long pulse width on a Candela Vbeam(R) PDL for treatment of PDL- and KTP laser-resistant nasal telangiectasia. Nasal telangiectasia resistant to PDL (12 patients) and KTP laser (12 patients) in 18 patients were treated with a 3 mm x 10 mm elliptical spot on the ultra-long pulse pulsed dye laser (ULPDL) utilising long pulse width [595 nm, 40 ms, double pulse, 30:20 dynamic cooling device (DCD)]. Six patients had previously received treatment with both PDL and KTP laser prior to ULPDL (40 treatments, range1-4, mean 2.2). Complete clearance was seen in ten patients, and eight patients displayed more than 80% improvement after ULPDL treatment. Self-limiting purpura occurred with round spot PDL and erythema with KTP laser and ULPDL. Subtle linear furrows along the treatment sites were seen in three patients treated with the KTP laser. ULPDL treatment delivered using a 3 mm x 10 mm elliptical spot was non-purpuric and highly effective in the treatment of nasal telangiectasia resistant to KTP laser and PDL.

Distilled water nasal provocation in hyperreactive patients.

PubMed

Baudoin, T; Anzic, S A; Kalogjera, L

1999-01-01

Nonisotonic aerosol may act as a provocation agent in the upper and lower airways of hyperreactive individuals. The purpose of the study was to compare the results of nasal challenge with distilled water in patients with allergic rhinitis to those with noninfective nonallergic rhinitis (NINAR), with respect to the potential clinical use of the obtained data. A group of 68 ambulatory patients with allergic rhinitis or NINAR (39 perennial allergic, 6 seasonal, 23 NINAR) were challenged with 10 mL of distilled water aerosol after the baseline active anterior rhinomanometry. Patients with nasal polyposis at endoscopy, significant unilateral septal deviation, positive bacteriologic swab, recent nasal surgery, and uncertain anamnestic data about the medication taken 6 weeks before the provocation were excluded from the study. After 10 minutes of nasal provocation, rhinomanometry was repeated to assess the response. In 15 patients of the perennial allergic group, the same measurements were performed after a 2-week oral antihistamine and topical steroid therapy. Nasal resistance was significantly increased on the more patent side of the nose after nasal provocation with distilled water aerosol in allergic patients in comparison to the nasal resistance before provocation. In the patients with NINAR, the provocation resulted in a significant rise on the more patent side, but the total nasal airway resistance (NAR) levels were also significantly increased. The systemic antihistamine and topical steroid 2-week therapy in patients with perennial allergic rhinitis significantly reduced the response to nasal distilled water provocation. Nasal provocation with distilled water aerosol is a cheap, simple, and acceptable method that provides useful clinical data on the level of nonspecific nasal hyperreactivity and the therapy success.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

PubMed

Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Comparative evaluation of three chromogenic media combined with broth enrichment and the real-time PCR-based Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus in nasal swabs.

PubMed

Lee, Seungok; Park, Yeon-Joon; Park, Kang-Gyun; Jekarl, Dong Wook; Chae, Hyojin; Yoo, Jin-Kyung; Seo, Sin Won; Choi, Jung Eun; Lim, Jung Hye; Heo, Seon Mi; Seo, Ju Hee

2013-07-01

We evaluated the performance of three chromogenic media (Brilliance agar I [Oxoid, UK], Brilliance agar II [Oxoid], and ChromID MRSA [Biomérieux, France]) combined with broth enrichment and the Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus (MRSA). We obtained 401 pairs of duplicate nasal swabs from 321 patients. One swab was suspended overnight in tryptic soy broth; 50-µL aliquots of suspension were inoculated on the three chromogenic media. Brilliance agar I and II were examined after 24 hr, and ChromID MRSA, after 24 and 48 hr. The paired swab was processed directly using real-time PCR-based Xpert MRSA assay. True positives, designated as MRSA growth in any of the culture media, were detected with the prevalence of 17% in our institution. We report the sensitivity, specificity, positive predictive value, and negative predictive value of MRSA growth as follows: 92.3%, 94.0%, 75.9%, and 98.4% in Brilliance agar I (24 hr); 92.7%, 97.9%, 90.0%, and 98.5% in Brilliance agar II (24 hr); 95.6%, 95.8%, 82.3%, and 99.1% in ChromID MRSA (24 hr); 100%, 92.5%, 73.1%, and 100% in ChromID MRSA (48 hr); 92.6%, 96.7%, 85.1%, and 98.5% in Xpert MRSA assay. The agreement between the enriched culture and Xpert MRSA assay was 96.0%. Three chromogenic culture media combined with enrichment and Xpert MRSA assay demonstrated similar capabilities in MRSA detection. The Xpert MRSA assay yielded results comparable to those of culture methods, saving 48-72 hr, thus facilitating earlier detection of MRSA in healthcare settings.

Nasal Airway Microbiota Profile and Severe Bronchiolitis in Infants: A Case-control Study.

PubMed

Hasegawa, Kohei; Linnemann, Rachel W; Mansbach, Jonathan M; Ajami, Nadim J; Espinola, Janice A; Petrosino, Joseph F; Piedra, Pedro A; Stevenson, Michelle D; Sullivan, Ashley F; Thompson, Amy D; Camargo, Carlos A

2017-11-01

Little is known about the relationship of airway microbiota with bronchiolitis in infants. We aimed to identify nasal airway microbiota profiles and to determine their association with the likelihood of bronchiolitis in infants. A case-control study was conducted. As a part of a multicenter prospective study, we collected nasal airway samples from 40 infants hospitalized with bronchiolitis. We concurrently enrolled 110 age-matched healthy controls. By applying 16S ribosomal RNA gene sequencing and an unbiased clustering approach to these 150 nasal samples, we identified microbiota profiles and determined the association of microbiota profiles with likelihood of bronchiolitis. Overall, the median age was 3 months and 56% were male. Unbiased clustering of airway microbiota identified 4 distinct profiles: Moraxella-dominant profile (37%), Corynebacterium/Dolosigranulum-dominant profile (27%), Staphylococcus-dominant profile (15%) and mixed profile (20%). Proportion of bronchiolitis was lowest in infants with Moraxella-dominant profile (14%) and highest in those with Staphylococcus-dominant profile (57%), corresponding to an odds ratio of 7.80 (95% confidence interval, 2.64-24.9; P < 0.001). In the multivariable model, the association between Staphylococcus-dominant profile and greater likelihood of bronchiolitis persisted (odds ratio for comparison with Moraxella-dominant profile, 5.16; 95% confidence interval, 1.26-22.9; P = 0.03). By contrast, Corynebacterium/Dolosigranulum-dominant profile group had low proportion of infants with bronchiolitis (17%); the likelihood of bronchiolitis in this group did not significantly differ from those with Moraxella-dominant profile in both unadjusted and adjusted analyses. In this case-control study, we identified 4 distinct nasal airway microbiota profiles in infants. Moraxella-dominant and Corynebacterium/Dolosigranulum-dominant profiles were associated with low likelihood of bronchiolitis, while Staphylococcus-dominant profile

Transmission of methicillin-resistant Staphylococcus pseudintermedius between infected dogs and cats and contact pets, humans and the environment in households and veterinary clinics.

PubMed

van Duijkeren, E; Kamphuis, M; van der Mije, I C; Laarhoven, L M; Duim, B; Wagenaar, J A; Houwers, D J

2011-06-02

The objective of this study was to investigate the prevalence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in people, pets and the environment in households with a pet with a clinical MRSP-infection within the past year. Personnel and the environment at veterinary clinics were also screened. Nasal swabs (humans), nasal and perineal swabs (pets) and environmental wipes were examined using selective culturing. Twenty households were enrolled; 10/20 index cases still had clinical signs of infection at the start of the study and all were MRSP-positive. Of the remaining 10 index cases five were MRSP-positive in nasal and/or perineal samples. Five of 14 (36%) contact dogs and four of 13 (31%) contact cats were found MRSP-positive. In the households with an index case with clinical signs of infection 6/7 (86%) contact animals were MRSP-positive. MRSP was cultured from 2/45 (4%) human nasal samples. Domestic contamination was widespread as positive samples were found in 70% of the households and 44% of all environmental samples were MRSP-positive. In all but one of these MRSP-positive households the index case was still MRSP positive. Among the personnel in veterinary clinics 4/141 (3%) were MRSP-positive. MRSP was cultured from 31/200 environmental samples in 7/13 clinics at the first sampling and in 3/6 clinics the environment remained MRSP-positive after cleaning and disinfection indicating that current cleaning procedures often were unable to eliminate MRSP. These results show that transmission of MRSP between infected or colonized dogs and cats and healthy people does occur but is relatively uncommon, while transmission to contact pets occurs frequently, especially when the index case still has clinical signs of MRSP-infection. Copyright © 2011 Elsevier B.V. All rights reserved.

Genotypic and Phenotypic Markers of Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC9 in Humans.

PubMed

Ye, Xiaohua; Wang, Xiaolin; Fan, Yanping; Peng, Yang; Li, Ling; Li, Shunming; Huang, Jingya; Yao, Zhenjiang; Chen, Sidong

2016-07-01

Use of antimicrobials in industrial food animal production is associated with the presence of multidrug-resistant Staphylococcus aureus among animals and humans. The livestock-associated (LA) methicillin-resistant S. aureus (MRSA) clonal complex 9 (CC9) is associated with animals and related workers in Asia. This study aimed to explore the genotypic and phenotypic markers of LA-MRSA CC9 in humans. We conducted a cross-sectional study of livestock workers and controls in Guangdong, China. The study participants responded to a questionnaire and provided a nasal swab for S. aureus analysis. The resulting isolates were assessed for antibiotic susceptibility, multilocus sequence type, and immune evasion cluster (IEC) genes. Livestock workers had significantly higher rates of S. aureus CC9 (odds ratio [OR] = 30.98; 95% confidence interval [CI], 4.06 to 236.39) and tetracycline-resistant S. aureus (OR = 3.26; 95% CI, 2.12 to 5.00) carriage than controls. All 19 S. aureus CC9 isolates from livestock workers were MRSA isolates and also exhibited the characteristics of resistance to several classes of antibiotics and absence of the IEC genes. Notably, the interaction analyses indicated phenotype-phenotype (OR = 525.7; 95% CI, 60.0 to 4,602.1) and gene-environment (OR = 232.3; 95% CI, 28.7 to 1,876.7) interactions associated with increased risk for livestock-associated S. aureus CC9 carriage. These findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact, raising questions about the potential for occupational exposure to opportunistic S. aureus This study adds to existing knowledge by giving insight into the genotypic and phenotypic markers of LA-MRSA. Our findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact. Future studies should direct more

Genotypic and Phenotypic Markers of Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC9 in Humans

PubMed Central

Ye, Xiaohua; Wang, Xiaolin; Fan, Yanping; Peng, Yang; Li, Ling; Li, Shunming; Huang, Jingya; Yao, Zhenjiang

2016-01-01

ABSTRACT Use of antimicrobials in industrial food animal production is associated with the presence of multidrug-resistant Staphylococcus aureus among animals and humans. The livestock-associated (LA) methicillin-resistant S. aureus (MRSA) clonal complex 9 (CC9) is associated with animals and related workers in Asia. This study aimed to explore the genotypic and phenotypic markers of LA-MRSA CC9 in humans. We conducted a cross-sectional study of livestock workers and controls in Guangdong, China. The study participants responded to a questionnaire and provided a nasal swab for S. aureus analysis. The resulting isolates were assessed for antibiotic susceptibility, multilocus sequence type, and immune evasion cluster (IEC) genes. Livestock workers had significantly higher rates of S. aureus CC9 (odds ratio [OR] = 30.98; 95% confidence interval [CI], 4.06 to 236.39) and tetracycline-resistant S. aureus (OR = 3.26; 95% CI, 2.12 to 5.00) carriage than controls. All 19 S. aureus CC9 isolates from livestock workers were MRSA isolates and also exhibited the characteristics of resistance to several classes of antibiotics and absence of the IEC genes. Notably, the interaction analyses indicated phenotype-phenotype (OR = 525.7; 95% CI, 60.0 to 4,602.1) and gene-environment (OR = 232.3; 95% CI, 28.7 to 1,876.7) interactions associated with increased risk for livestock-associated S. aureus CC9 carriage. These findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact, raising questions about the potential for occupational exposure to opportunistic S. aureus. IMPORTANCE This study adds to existing knowledge by giving insight into the genotypic and phenotypic markers of LA-MRSA. Our findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact. Future studies

Preventing Community-Associated Methicillin-Resistant "Staphylococcus aureus" among Student Athletes

ERIC Educational Resources Information Center

Many, Patricia S.

2008-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) was once thought to be a bacterium causing infections in only hospitalized patients. However, a new strain of MRSA has emerged among healthy individuals who have not had any recent exposure to a hospital or to medical procedures. This new strain is known as "community-associated…

Molecular Types of Methicillin-Resistant Staphylococcus aureus and Methicillin-Sensitive S. aureus Strains Causing Skin and Soft Tissue Infections and Nasal Colonization, Identified in Community Health Centers in New York City.

PubMed

Pardos de la Gandara, Maria; Raygoza Garay, Juan Antonio; Mwangi, Michael; Tobin, Jonathan N; Tsang, Amanda; Khalida, Chamanara; D'Orazio, Brianna; Kost, Rhonda G; Leinberger-Jabari, Andrea; Coffran, Cameron; Evering, Teresa H; Coller, Barry S; Balachandra, Shirish; Urban, Tracie; Parola, Claude; Salvato, Scott; Jenks, Nancy; Wu, Daren; Burgess, Rhonda; Chung, Marilyn; de Lencastre, Herminia; Tomasz, Alexander

2015-08-01

In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureus strains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureus were collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus (MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus (MSSA) was recovered from 24. Most-46 of the 63-wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL(+)) group of S. aureus clone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureus infections, 30 were also colonized by S. aureus in the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Antimicrobial effects of lysophosphatidylcholine on methicillin-resistant Staphylococcus aureus.

PubMed

Miyazaki, Haruko; Midorikawa, Naoko; Fujimoto, Saki; Miyoshi, Natsumi; Yoshida, Hideto; Matsumoto, Tetsuya

2017-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important health care-associated and community-associated pathogen and causes a large number of infections worldwide. For the purpose of application to topical treatment of MRSA infection, we examined the antimicrobial effects of lysophosphatidylcholine (LPC) on MRSA strains. We also investigated the combination effect of LPC and gentamicin on MRSA growth. The LPC minimum inhibitory concentrations (MIC) for Gram-positive ( S. aureus, Staphylococcus epidermidis , and Streptococcus pneumoniae ) and Gram-negative ( Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae , and Pseudomonas aeruginosa ) bacteria were measured by the broth microdilution method. The mechanism of LPC-mediated MRSA killing was investigated by membrane permeability analysis with DiSC3(5) fluorescence and growth curve analysis. Lastly, the effects of LPC on gentamicin-induced bactericidal activity were determined in combination treatment studies with 15 gentamicin-resistant MRSA isolates from the skin, nose, or ears. The LPC MIC for Gram-positive bacteria varied between 32 µg/ml and >2048 µg/ml, whereas that for all Gram-negative bacteria was >2048 µg/ml. Consistently, membrane permeability analysis showed that LPC was substantially more effective in inducing membrane permeability in Gram-positive bacteria than in Gram-negative counterparts. Growth curve analysis in cotreatment studies demonstrated that LPC has intrinsic bactericidal effects and can also potentiate gentamicin sensitivity in resistant MRSA strains. Our study demonstrates that LPC exhibits intrinsic antimicrobial effects and can enhance the antimicrobial effects of gentamicin for resistant MRSA strains, suggesting that LPC may be a beneficial additive in topical antibiotics for superficial skin infections.

[Antibiotic susceptibility of Staphylococcus aureus and Streptococcus pneumoniae in healthy carrier individuals in primary care in Barcelona area].

PubMed

Llor, Carles; Boada, Albert; Pons-Vigués, Mariona; Grenzner, Elisabet; Juvé, Rosa; Almeda, Jesús

2018-01-01

The information available on antibiotic resistance patterns are generally based on specimens from hospitalised individuals. This study was aimed at evaluating the antibiotic resistance rate of nasal carriage strains of Staphylococcus aureus and Streptococcus pneumoniae in healthy individuals, in accordance with age and gender, attended in Primary Care Centres (PCC). Cross-sectional study. Seven PCC in the Barcelona area. Healthy nasal carriers aged 4years or more who did not present with any sign of infectious disease, and had not taken any antibiotic or had been hospitalised in the previous 3months. A total of 3,969 nasal swabs valid for identification were collected between 2010 and 2011 and were sent to one central microbiological laboratory for isolation of both pathogens. Resistance to common antibiotics was determined on the basis of the current European Committee on Antimicrobial Susceptibility Testing guidelines on cut-off points. The prevalence of methicillin-resistant S.aureus was 1.3% (95%CI: 0.5-2.1%), with resistance rates of 87.1% to phenoxymethylpenicillin and 11.6% to azithromycin, with no significant differences with age and gender. A total of 2.4% (95CI%: 0.1-4.7%) of the pneumococcal strains were highly resistant to both phenoxymethylpenicillin and macrolides, whereas the highest resistance rates were to cefaclor (53.3%), followed by tetracycline (20%) and cefuroxime (12.1%). These pathogens have lower resistance rates in the community than in the hospital setting. Primary Care physicians must be more aware of the current antimicrobial resistance, in order to ensure prudent use of antibiotics. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Molecular characterization of nasal methicillin resistant Staphylococcus aureus isolates from workers of an automaker company in southeast Iran.

PubMed

Sobhanipoor, Mohammad Hossein; Ahmadrajabi, Roya; Karmostaji, Afsaneh; Saffari, Fereshteh

2017-10-01

Colonization of methicillin resistant Staphylococccus aureus (MRSA) can occur more commonly in healthy people who live in close together or are in close physical contact with each other. Having knowledge about the molecular characteristics of these strains provides considerable discernment into the epidemiology of this important microorganism. A total of 806 nasal swabs were collected from healthy workers of an automaker company in the southeast of Iran and were analyzed to detect MRSA isolates. Multilocus sequence typing (MLST), spa typing, and detection of staphylococcal cassette chromosome mec (SCCmec) were performed. The presence of genes encoding Panton-Valentine Leukocidin (PVL) and Arginine Catabolic Mobile Element (ACME) were also investigated. Carriage rate of S. aureus was 20%. Among 10 identified MRSA, no acme was found while high prevalence of pvl (60%) was of great concern. Seven different spa types including five new ones were identified. The most frequent sequence type was the novel one; ST 3373 (n = 3), followed by each of ST22, ST88, ST859 (n = 2) and ST1955 (n = 1). MRSA isolates were clustered into two main clonal complexes; CC22 (n = 6) and CC88 (n = 4). Low genetic diversity with the dominance of CC22, SCCmecIV was found. Distribution of previously found hospital-associated MRSA was demonstrated among our isolates. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Infection with methicillin-resistant Staphylococcus pseudintermedius masquerading as cefoxitin susceptible in a dog.

PubMed

Weese, J Scott; Faires, Meredith; Brisson, Brigette A; Slavic, Durda

2009-11-01

A 2-year-old dog was evaluated because of complications that developed following tibial plateau leveling osteotomy. Infection of the surgical site developed following removal of the failed implant. The dog was lame with evidence of a deep surgical site infection, and Staphylococcus pseudintermedius was isolated from the surgical site. Results of in vitro testing indicated that the isolate was resistant to multiple antimicrobials but susceptible to cefoxitin. Subsequent testing confirmed that the isolate was methicillin-resistant S pseudintermedius and was in fact resistant to cefoxitin. On the basis of results of follow-up testing, doxycycline was administered before and after surgery to remove the surgical implant. The dog recovered without further complications. Findings suggested that certain strains of methicillin-resistant S pseudintermedius, which appears to be an emerging pathogen in dogs, may be falsely identified as methicillin susceptible on the basis of results of testing for cefoxitin susceptibility because cefoxitin may not induce the mecA gene as reliably in S pseudintermedius as it does in Staphylococcus aureus. Isolates of S pseudintermedius should be considered to likely be methicillin resistant when multidrug resistance is identified, even if susceptibility to some beta-lactam antimicrobials is reported.

New drugs for methicillin-resistant Staphylococcus aureus: an update.

PubMed

Kumar, Krishan; Chopra, Sidharth

2013-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) remains a leading cause of bacterial infections worldwide, with a dwindling repertoire of effective antimicrobials active against it. This review aims to provide an update on novel anti-MRSA molecules currently under pre-clinical and clinical development, with emphasis on their mechanism of action. This review is limited to molecules that target the pathogen directly and does not detail immunomodulatory anti-infectives.

Unveiling the molecular basis of antimicrobial resistance in Staphylococcus aureus from the Democratic Republic of the Congo using whole genome sequencing.

PubMed

Phaku, P; Lebughe, M; Strauß, L; Peters, G; Herrmann, M; Mumba, D; Mellmann, A; Muyembe-Tamfum, J-J; Schaumburg, F

2016-07-01

Staphylococcus aureus from sub-Saharan Africa is frequently resistant to antimicrobial agents that are commonly used to treat invasive infections in resource-limited settings. The underlying mechanisms of resistance are largely unknown. We therefore performed whole genome sequencing (WGS) on S. aureus from the Democratic Republic of the Congo (DRC) to analyse the genetic determinants of antimicrobial resistance. One hundred S. aureus samples were collected from community-associated asymptomatic nasal carriers in the metropolitan area of Kinshasa, DRC, between 2013 and 2014. Phenotypic resistance against 15 antimicrobial agents was compared to the genotypic results that were extracted from WGS data using Mykrobe predictor and the SeqSphere(+) software that screened for 106 target genes associated with resistance. Isolates were phenotypically resistant against penicillin (97%, n=97), trimethoprim (72%, n=72) and tetracycline (54%, n=45). Thirty-three isolates (33%) were methicillin-resistant S. aureus (MRSA). Of these, nine isolates (27.3%) were oxacillin-susceptible MRSA (OS-MRSA) and belonged to ST8 (t1476). The Y195F mutation of FemA was associated with OS-MRSA (p 0.015). The majority of trimethoprim resistant isolates carried dfrG. Tetracycline resistance was associated with tet(K). The concordance between phenotypic susceptibility testing and both WGS analysis tools was similar and ranged between 96% and 100%. In conclusion, a high proportion of OS-MRSA in the DRC was linked to mutations of FemA. Genotypic and phenotypical antimicrobial susceptibility testing showed high concordance. This encourages the future use of WGS in routine antimicrobial susceptibility testing. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis--three cases reported from India.

PubMed

Bandyopadhyay, Samiran; Samanta, Indranil; Bhattacharyya, Debaraj; Nanda, Pramod Kumar; Kar, Debasish; Chowdhury, Jayanta; Dandapat, Premanshu; Das, Arun Kumar; Batul, Nayan; Mondal, Bimalendu; Dutta, Tapan Kumar; Das, Gunjan; Das, Bikash Chandra; Naskar, Syamal; Bandyopadhyay, Uttam Kumar; Das, Suresh Chandra; Bandyopadhyay, Subhasish

2015-03-01

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistance to various antibiotics such as amikacin, tetracycline and glycopeptides. The ESBL producers were positive for blaCTX-M and blaTEM genes; in addition, HFEC1 and HFEC2 were positive for blaSHV and possessed the genes for class I integron (int1), sulphonamide resistance (sul1), quinolone resistance (qnrS) and other virulence factors (papC, iucD and ESTA1). All the ESBL producers exhibited resistance to a variety of antibiotics tested including third- and fourth-generation cephalosporins and were also intermediately resistant to carbapenems. This is the first ever report on simultaneous occurrence of MRSE, MRSA and ESBL producing E. coli in bovine mastitis indicating a major concern for dairy industry and public health as well.

Methicillin-Resistant Staphylococcus aureus in Pork Production Shower Facilities ▿

PubMed Central

Leedom Larson, Kerry R.; Harper, Abby L.; Hanson, Blake M.; Male, Michael J.; Wardyn, Shylo E.; Dressler, Anne E.; Wagstrom, Elizabeth A.; Tendolkar, Shaliesh; Diekema, Daniel J.; Donham, Kelley J.; Smith, Tara C.

2011-01-01

As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746. PMID:21097587

Antimicrobial resistance 1979-2009 at Karolinska hospital, Sweden: normalized resistance interpretation during a 30-year follow-up on Staphylococcus aureus and Escherichia coli resistance development.

PubMed

Kronvall, Göran

2010-09-01

To utilize a material of inhibition zone diameter measurements from disc diffusion susceptibility tests between 1979 and 2009, an objective setting of epidemiological breakpoints was necessary because of methodological changes. Normalized resistance interpretation (NRI) met this need and was applied to zone diameter histograms for Staphylococcus aureus and Escherichia coli isolates. The results confirmed a slow resistance development as seen in Northern countries. The S. aureus resistance levels for erythromycin, clindamycin and fusidic acid in 2009 were 3.2%, 1.8% and 1.4% with denominator correction. A rise in resistance to four antimicrobials in 1983 was probably because of a spread of resistant Methicillin Susceptible Staphylococcus Aureus (MSSA). For E. coli, the denominator-corrected resistance levels in 2009 were 27% for ampicillin, around 3% for third-generation cephalosporins, 0.1% for imipenem, 2.5% for gentamicin, 19% for trimethoprim, 4.5% for co-trimoxazole, 1.2% for nitrofurantoin and 9% for ciprofloxacin. The temporal trends showed a rise in fluoroquinolone resistance from 1993, a parallel increase in gentamicin resistance, a substantial increase in trimethoprim and sulphonamide resistance in spite of decreased consumption, and a steady rise in ampicillin resistance from a constant level before 1989. A short review of global resistance surveillance studies is included.

Prevalence of Chlorhexidine-Resistant Methicillin-Resistant Staphylococcus aureus following Prolonged Exposure

PubMed Central

Millar, Eugene V.; Crawford, Katrina B.; Cui, Tianyuan; Lanier, Jeffrey B.; Tribble, David R.; Ellis, Michael W.

2014-01-01

Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts. PMID:24841265

Vancomycin Ophthalmic Ointment 1% for methicillin-resistant Staphylococcus aureus or methicillin-resistant Staphylococcus epidermidis infections: a case series

PubMed Central

Sotozono, Chie; Fukuda, Masahiko; Ohishi, Masao; Yano, Keiko; Origasa, Hideki; Saiki, Yoshinori; Shimomura, Yoshikazu; Kinoshita, Shigeru

2013-01-01

Objectives To investigate the efficacy and safety of Vancomycin Ophthalmic Ointment 1% (Toa Pharmaceutical Co., Ltd, Toyama, Japan) in patients with external ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE). Design A case series. Setting This study was a multicentre, open-label, uncontrolled study in Japan approved as orphan drug status. Participants Patients with MRSA or MRSE external ocular infections unresponsive to the treatment of fluoroquinolone eye drops. Interventions Vancomycin Ophthalmic Ointment 1% was administered four times daily. Primary and secondary outcome measures The subjective and objective clinical scores and bacterial cultures were collected at days 0 (baseline), 3, 7 and 14. The primary outcome was clinical response evaluation (efficacy rate) determined as complete response, partial response, no response and worsening. Secondary outcome was the eradication of the bacteria. Safety was assessed by adverse events including cases in which neither MRSA nor MRSE was detected. Results Twenty-five cases with MRSA (20) or MRSE (5) infections were enrolled. Of these 25 cases, 4 discontinued the treatment due to the negative results for bacterial culture during screening or at baseline. Of the 21 cases with conjunctivitis (14), blepharitis (3), meibomitis (1), dacryocystitis (2) or keratitis (1), 14 (66.7%) cases were evaluated as being excellently (complete response, 2 cases) or well (partial response, 12 cases) treated. The eradication rates were 68.4% in MRSA (13 of 19 cases) and 100% in MRSE (2 of 2 cases). Ten adverse events occurred in 7 (28.0%) of 25 cases at the local administration site. Conclusions Vancomycin Ophthalmic Ointment 1% was considered to be useful for the treatment of intractable ocular MRSA/MRSE infections. PMID:23364319

Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus.

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

Antimicrobial effects of lysophosphatidylcholine on methicillin-resistant Staphylococcus aureus

PubMed Central

Miyazaki, Haruko; Midorikawa, Naoko; Fujimoto, Saki; Miyoshi, Natsumi; Yoshida, Hideto; Matsumoto, Tetsuya

2017-01-01

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is an important health care-associated and community-associated pathogen and causes a large number of infections worldwide. For the purpose of application to topical treatment of MRSA infection, we examined the antimicrobial effects of lysophosphatidylcholine (LPC) on MRSA strains. We also investigated the combination effect of LPC and gentamicin on MRSA growth. Methods: The LPC minimum inhibitory concentrations (MIC) for Gram-positive (S. aureus, Staphylococcus epidermidis, and Streptococcus pneumoniae) and Gram-negative (Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa) bacteria were measured by the broth microdilution method. The mechanism of LPC-mediated MRSA killing was investigated by membrane permeability analysis with DiSC3(5) fluorescence and growth curve analysis. Lastly, the effects of LPC on gentamicin-induced bactericidal activity were determined in combination treatment studies with 15 gentamicin-resistant MRSA isolates from the skin, nose, or ears. Results: The LPC MIC for Gram-positive bacteria varied between 32 µg/ml and >2048 µg/ml, whereas that for all Gram-negative bacteria was >2048 µg/ml. Consistently, membrane permeability analysis showed that LPC was substantially more effective in inducing membrane permeability in Gram-positive bacteria than in Gram-negative counterparts. Growth curve analysis in cotreatment studies demonstrated that LPC has intrinsic bactericidal effects and can also potentiate gentamicin sensitivity in resistant MRSA strains. Conclusions: Our study demonstrates that LPC exhibits intrinsic antimicrobial effects and can enhance the antimicrobial effects of gentamicin for resistant MRSA strains, suggesting that LPC may be a beneficial additive in topical antibiotics for superficial skin infections. PMID:28748087

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) at a palliative care unit: A prospective single service analysis.

PubMed

Heckel, Maria; Geißdörfer, Walter; Herbst, Franziska A; Stiel, Stephanie; Ostgathe, Christoph; Bogdan, Christian

2017-01-01

The emergence of multidrug-resistant bacterial microorganisms is a particular challenge for the health care systems. Little is known about the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Gram-negative bacteria (MDRGNB) in patients of palliative care units (PCU). The primary aim of this study was to determine the carriage of MRSA among patients of a PCU at a German University Hospital and to assess whether the positive cases would have been detected by a risk-factor-based screening-approach. Between February 2014 and January 2015 patients from our PCU were tested for MRSA carriage within 48 hours following admission irrespective of pre-existing risk factors. In addition, risk factors for MRSA colonization were assessed. Samples from the nostrils and, if applicable, from pre-existing wounds were analysed by standardized culture-based laboratory techniques for the presence of MRSA and of other bacteria and fungi. Results from swabs taken prior to admission were also recorded if available. 297 out of 317 patients (93.7%) fulfilled one or more MRSA screening criteria. Swabs from 299 patients were tested. The detection rate was 2.1% for MRSA. All MRSA cases would have been detected by a risk-factor-based screening-approach. Considering the detected cases and the results from swabs taken prior to admission, 4.1% of the patients (n = 13) were diagnosed with MRSA and 4.1% with MDRGNB (n = 13), including two patients with MRSA and MDRGNB (0.6%). The rate of MRSA carriage in PCU patients (4.1%) was elevated compared to the rate seen in the general cohort of patients admitted to our University Hospital (2.7%). PCU patients have an increased risk to carry MRSA compared to other hospitalized patients. Although a risk factor-based screening is likely to detect all MRSA carriers amongst PCU patients, we rather recommend a universal screening to avoid the extra effort to identify the few risk factor-negative patients (<7%). As we did not

Nasal inflammation in sleep apnoea patients using CPAP and effect of heated humidification.

PubMed

Koutsourelakis, I; Vagiakis, E; Perraki, E; Karatza, M; Magkou, C; Kopaka, M; Roussos, C; Zakynthinos, S

2011-03-01

Nasal continuous positive airway pressure (CPAP) can cause undesirable nasal symptoms, such as congestion to obstructive sleep apnoea (OSA) patients, whose symptoms can be attenuated by the addition of heated humidification. However, neither the nature of nasal symptoms nor the effect of heated humidification on nasal pathophysiology and pathology are convincingly known. 20 patients with OSA on nasal CPAP who exhibited symptomatic nasal obstruction were randomised to receive either 3 weeks of CPAP treatment with heated humidification or 3 weeks of CPAP treatment with sham-heated humidification, followed by 3 weeks of the opposite treatment, respectively. Nasal symptom score, nasal resistance, nasal lavage interleukin-6, interleukin-12 and tumour necrosis factor-α and nasal mucosa histopathology were assessed at baseline and after each treatment arm. Heated humidification in comparison with sham-heated humidification was associated with decrease in nasal symptomatology, resistance and lavage cytokines, and attenuation of inflammatory cell infiltration and fibrosis of the nasal mucosa. In conclusion, nasal obstruction of OSA patients on CPAP treatment is inflammatory in origin and the addition of heated humidification decreases nasal resistance and mucosal inflammation.

Worldwide Endemicity of a Multidrug-Resistant Staphylococcus capitis Clone Involved in Neonatal Sepsis.

PubMed

Butin, Marine; Martins-Simões, Patricia; Rasigade, Jean-Philippe; Picaud, Jean-Charles; Laurent, Frédéric

2017-03-01

A multidrug-resistant Staphylococcus capitis clone, NRCS-A, has been isolated from neonatal intensive care units in 17 countries throughout the world. S. capitis NRCS-A prevalence is high in some neonatal intensive care units in France. These data highlight the worldwide endemicity and epidemiologic relevance of this multidrug-resistant, coagulase-negative staphylococci clone.

Methicillin-Resistant Staphylococcus aureus Prevalence among Captive Chimpanzees, Texas, USA, 20121

PubMed Central

Barnhart, Kirstin F.; Abee, Christian R.; Lambeth, Susan P.; Weese, J. Scott

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) infection in humans and animals is concerning. In 2012, our evaluation of a captive chimpanzee colony in Texas revealed MRSA prevalence of 69%. Animal care staff should be aware of possible zoonotic MRSA transmission resulting from high prevalence among captive chimpanzees. PMID:26583847

Prevalence and antimicrobial resistance profile of Staphylococcus in dairy farms, abattoir and humans in Addis Ababa, Ethiopia.

PubMed

Beyene, Takele; Hayishe, Halefom; Gizaw, Fikru; Beyi, Ashenafi Feyisa; Abunna, Fufa; Mammo, Bedaso; Ayana, Dinka; Waktole, Hika; Abdi, Reta Duguma

2017-04-28

Staphylococcus species cause mastitis and wound infection in livestock and food poisoning in humans through ingestion of contaminated foods, including meat and dairy products. They are evolving pathogens in that they readily acquire drug resistance, and multiple drug-resistant (MDR) isolates are increasing in human and veterinary healthcare. Therefore, this study was conducted to evaluate the prevalence of Staphylococci and their drug resistance in dairy farms and abattoir settings of Addis Ababa. In this cross-sectional study, 193 samples of milk, meat, equipment and humans working in the dairy farms and abattoir were collected (dairy farms = 72 and abattoir sources = 121). Staphylococcus isolation and identification at the species level was done according to ISO-6888-3 using biochemical characteristics. An antimicrobial susceptibility test was conducted for 43 of the isolates using 15 antimicrobial agents commonly used for humans and livestock by the Kirby Bauer disk diffusion method following CLSI guidelines. Staphylococcus organism were isolated from 92 (47.7%) of the total 193 samples, 50% in the dairy farms and 46.3% in the abattoir. The isolated species were S. aureus (n = 31; 16.1%), S. intermedius (n = 21; 10.9%), S. hyicus (n = 16; 8.3%), and coagulase negative Staphylococcus (CNS) (n = 24; 12.4%). Gentamycin was effective drug as all isolates (n = 43; 100%) were susceptible to it and followed by kanamycin (n = 39; 90.7%). However, the majority of the isolates showed resistance to penicillin-G (95.3%), nalidixic acid (88.4%), cloxacillin (79.1%), vancomycin (65.1%) and cefoxitin (55.8%). Of the 15 S. aureus tested for drug susceptibility, 73.3% of them were phenotypically resistant to vancomycin (VRSA) and all of the 15 isolates showed multi-drug resistance (MDR) to >3 drugs. Also, all of the tested CNS (100%), S. hyicus (100%) and the majority of S. intermedius isolates (88.9%) developed MDR. Alarmingly, the Staphylococcus isolates

The detection and differentiation of methicillin-resistant and methicillin-susceptible Staphylococcus aureus endocarditis by using the BD GeneOhm StaphSR Assay.

PubMed

Frey, Amy B; Wilson, Deborah A; LaSalvia, Margaret M; Tan, Carmela D; Rodriguez, E Rene; Shrestha, Nabin K; Hall, Gerri S; Procop, Gary W

2011-11-01

We use the BD GeneOhm StaphSR Assay (BD Diagnostics, Oakville, Canada) to screen for Staphylococcus aureus nasal colonization and sought to evaluate this assay for the assessment of valve specimens from patients with endocarditis. We examined 23 paired fresh and formalin-fixed, paraffin-embedded cardiac valve tissue samples, 12 of which had S aureus endocarditis, using the BD GeneOhm StaphSR Assay for the detection and differentiation of methicillin-susceptible and methicillin-resistant S aureus. This assay appropriately characterized all specimens with respect to the presence or absence of S aureus. There was an 87.5% correlation between the presence or absence of the mecA gene and the oxacillin susceptibility results for the S aureus isolates studied. The GeneOhm StaphSR assay accurately detected S aureus in cardiac valve tissue samples. Rare discordances were observed between oxacillin susceptibility status and mecA gene detection by this assay.

Antibiotic resistance in Staphylococcus sp. isolated from the vaginal environment of squirrel monkeys (Saimiri spp.) bred ex situ.

PubMed

Donato, Anna C J; Penna, Bruno; Consalter, Angélica; Carvalho, Daniela D; Lilenbaum, Walter; Ferreira, Ana M R

2017-06-01

Squirrel monkeys (Saimiri spp.) have been widely used as animal models; however, the occurrence of Staphylococcus sp in their vaginal microbiota remains to be described. Samples were collected from 175 adult squirrel monkeys to isolate Staphylococcus sp and to test for susceptibility to a panel of nine antimicrobial agents. Isolates with characteristics of the genus Staphylococcus were detected in 95 of 175 samples. Coagulase-negative staphylococci (CoNS) were the most common (95.8%, 91/95) isolates. Resistance to antibiotics was observed in 47.3% (45/95) of isolates. Resistance to tetracycline was observed in 28.5% (26/91), chloramphenicol in 15.4% (14/91), and methicillin in 13.2% (12/91) of CoNS. Coagulase-positive staphylococci were resistant to tetracycline, erythromycin, and methicillin. The presence of Staphylococcus sp in vaginal samples obtained from squirrel monkeys suggests that these animals were in a carrier state. Furthermore, isolating strains resistant to methicillin reinforces the biosafety care of a colony. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

PubMed

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Induced resistance to the antimicrobial peptide lactoferricin B in Staphylococcus aureus.

PubMed

Samuelsen, Orjan; Haukland, Hanne H; Jenssen, Håvard; Krämer, Manuela; Sandvik, Kjersti; Ulvatne, Hilde; Vorland, Lars H

2005-06-20

This study was designed to investigate inducible intrinsic resistance against lactoferricin B in Staphylococcus aureus. Serial passage of seven S. aureus strains in medium with increasing concentrations of peptide resulted in an induced resistance at various levels in all strains. The induced resistance was unstable and decreased relatively rapidly during passages in peptide free medium but the minimum inhibitory concentration remained elevated after thirty passages. Cross-resistance to penicillin G and low-level cross-resistance to the antimicrobial peptides indolicidin and Ala(8,13,18)-magainin-II amide [corrected] was observed. No cross-resistance was observed to the human cathelicidin LL-37. In conclusion, this study shows that S. aureus has intrinsic resistance mechanisms against antimicrobial peptides that can be induced upon exposure, and that this may confer low-level cross-resistance to other antimicrobial peptides.

Comparative evaluation of MRSA nasal colonization epidemiology in the urban and rural secondary school community of Kurdistan, Iraq.

PubMed

Hussein, Nawfal R; Basharat, Zarrin; Muhammed, Ary H; Al-Dabbagh, Samim A

2015-01-01

To study the nasal carriage rate of Staphylococcus aureus (S. aureus) (including methicillin-resistant strains) in secondary school community of the urban and rural districts of the Kurdistan region of Iraq, a cross-sectional population based survey was carried out in the city Duhok and rural areas of Amedya, Akre and Zakho. Nasal swabs were obtained from nostrils of 509 students aged 14-23 years. Resistance to methicillin was assessed by Kirby-Bauer disk diffusion and agar dilution assay. Vancomycin sensitivity was also tested on Muller-Hinton agar. It was found that the frequency of overall S. aureus nasal carriage (SANC) was 17.75% (90/509, CI95, 14.58-21.42%). In urban areas, the carriage rate was 20.59% (49/239, CI95, 15.64-26.29%), whereas it was 15.24% (41/270, CI95, 11.17-20.10%) in rural districts. The frequency of methicillin-resistant S. aureus (MRSA) among the isolated strains was found to be 2.04% (1/49) and 21.95% (9/41) in urban and rural areas respectively. It was found that in urban residents, the odd ratio (OR) of acquiring SANC was 1.44 (CI95, 0.91-2.27%) and risk ratio (RR) was at least 1.35 (CI95, 0.92-1.96%) while OR decreased to 0.12 (CI95, 0.01-0.96%) for MRSA carriage. Hence, the S. aureus carriage rate was higher in urban districts compared to rural areas while more MRSA were found in rural areas compared to urban districts. All studied strains were sensitive to vancomycin. This study provided baseline information for S. aureus nasal colonization in the region. Also, it showed that living in rural areas increased the odds of MRSA colonization. More attention should be paid to control MRSA colonization in rural communities.

Comparative Evaluation of MRSA Nasal Colonization Epidemiology in the Urban and Rural Secondary School Community of Kurdistan, Iraq

PubMed Central

Hussein, Nawfal R.; Basharat, Zarrin; Muhammed, Ary H.; Al-Dabbagh, Samim A.

2015-01-01

Background To study the nasal carriage rate of Staphylococcus aureus (S. aureus) (including methicillin-resistant strains) in secondary school community of the urban and rural districts of the Kurdistan region of Iraq, a cross-sectional population based survey was carried out in the city Duhok and rural areas of Amedya, Akre and Zakho. Methods Nasal swabs were obtained from nostrils of 509 students aged 14-23 years. Resistance to methicillin was assessed by Kirby-Bauer disk diffusion and agar dilution assay. Vancomycin sensitivity was also tested on Muller-Hinton agar. Results It was found that the frequency of overall S. aureus nasal carriage (SANC) was 17.75% (90/509, CI95, 14.58–21.42%). In urban areas, the carriage rate was 20.59% (49/239, CI95, 15.64–26.29%), whereas it was 15.24% (41/270, CI95, 11.17–20.10%) in rural districts. The frequency of methicillin-resistant S. aureus (MRSA) among the isolated strains was found to be 2.04% (1/49) and 21.95% (9/41) in urban and rural areas respectively. It was found that in urban residents, the odd ratio (OR) of acquiring SANC was 1.44 (CI95, 0.91-2.27%) and risk ratio (RR) was at least 1.35 (CI95, 0.92-1.96%) while OR decreased to 0.12 (CI95, 0.01-0.96%) for MRSA carriage. Hence, the S. aureus carriage rate was higher in urban districts compared to rural areas while more MRSA were found in rural areas compared to urban districts. All studied strains were sensitive to vancomycin. Conclusion This study provided baseline information for S. aureus nasal colonization in the region. Also, it showed that living in rural areas increased the odds of MRSA colonization. More attention should be paid to control MRSA colonization in rural communities. PMID:25932644

Occurrence, species distribution, antimicrobial resistance and clonality of methicillin- and erythromycin-resistant staphylococci in the nasal cavity of domestic animals.

PubMed

Bagcigil, Funda A; Moodley, Arshnee; Baptiste, Keith E; Jensen, Vibeke F; Guardabassi, Luca

2007-04-15

beta-Lactams and macrolides are important antibiotics for treatment of staphylococcal infections in both humans and animals. The aim of the study was to investigate the occurrence, species distribution and clonality of methicillin- and erythromycin-resistant staphylococci in the nasal cavity of dogs, horses, pigs, and cattle in Denmark. Nasal swabs were collected from a total of 400 animals, including 100 individuals of each species. Methicillin- and erythromycin-resistant staphylococci were isolated on selective media, identified by 16S rDNA sequencing, and typed by pulsed field gel electrophoresis (PFGE). Methicillin-resistant coagulase-negative staphylococci (MRCoNS) harbouring mecA were isolated from horses (50%) and dogs (13%), but not from food animals. The species identified were S. haemolyticus (n=21), S. vitulinus (n=19), S. sciuri (n=13), S. epidermidis (n=8), and S. warneri (n=2). mecA-mediated methicillin resistance in S. vitulinus was described for the first time. Methicillin-resistant S. aureus was not detected. PFGE analysis revealed the presence of specific MRCoNS clones in samples originating from the same veterinary hospital or equine farm. Erythromycin-resistant S. aureus (ERSA) was detected in 38% of pigs and all isolates harboured a constitutively expressed erm(C) gene. The vast majority (37/38) of pigs carrying ERSA originated from a farm characterized by frequent use of macrolides. Most ERSA isolates (28/38) displayed indistinguishable or closely related PFGE patterns, indicating clonal distribution within the farm. Based on the analysis of data on antimicrobial consumption, the occurrence of MRCoNS in companion animals and that of ERSA in pigs reflected national and local patterns of antimicrobial usage.

Detection of methicillin-resistant Staphylococcus aureus by a duplex droplet digital PCR assay.

PubMed

Kelley, Kashonda; Cosman, Angela; Belgrader, Phillip; Chapman, Brenda; Sullivan, Donna C

2013-07-01

Health care-associated infections with methicillin-resistant Staphylococcus aureus (MRSA) contribute to significant hospitalization costs. We report here a droplet digital PCR (ddPCR) assay, which is a next-generation emulsion-based endpoint PCR assay for high-precision MRSA analysis. Reference cultures of MRSA, methicillin-susceptible S. aureus (MSSA), and confounders were included as controls. Copan swabs were used to sample cultures and collect specimens for analysis from patients at a large teaching hospital. Swab extraction and cell lysis were accomplished using magnetic-driven agitation of silica beads. Quantitative PCR (qPCR) (Roche Light Cycler 480) and ddPCR (Bio-Rad QX100 droplet digital PCR system) assays were used to detect genes for the staphylococcal protein SA0140 (SA) and the methicillin resistance (mecA) gene employing standard TaqMan chemistries. Both qPCR and ddPCR assays correctly identified culture controls for MRSA (76), MSSA (12), and confounder organisms (36) with 100% sensitivity and specificity. Analysis of the clinical samples (211 negative and 186 positive) collected during a study of MRSA nasal carriage allowed direct comparison of the qPCR and ddPCR assays to the Cepheid MRSA GeneXpert assay. A total of 397 clinical samples were examined in this study. Cepheid MRSA GeneXpert values were used to define negative and positive samples. Both the qPCR and ddPCR assays were in good agreement with the reference assay. The sensitivities for the qPCR and ddPCR assays were 96.8% (95% confidence interval [CI], 93.1 to 98.5%) and 96.8% (95% CI, 93.1 to 98.5%), respectively. Both the qPCR and ddPCR assays had specificities of 91.9% (95% CI, 87.5 to 94.9%) for qPCR and 91.0% (95% CI, 86.4 to 94.2%) for ddPCR technology.

Trends in incidence and resistance patterns of Staphylococcus aureus bacteremia.

PubMed

Jokinen, Elina; Laine, Janne; Huttunen, Reetta; Lyytikäinen, Outi; Vuento, Risto; Vuopio, Jaana; Syrjänen, Jaana

2018-01-01

Staphylococcus aureus bacteremia (SAB) causes a significant burden on the population. Several infection control measures have been implemented in Pirkanmaa county to combat a local epidemic with methicillin-resistant Staphylococcus aureus (MRSA). We aimed to study the epidemiology of SAB and antibiotic resistance of S. aureus and the possible influence of improved infection control. Register data from 2005 to 2015 were retrospectively analysed to study the antimicrobial susceptibility, the incidence and mortality in SAB in a population-based setting. The incidence of SAB increased during the study period from 21.6 to 35.8/100,000 population. The number of both health care-associated (HA) and community-associated (CA) cases has increased. The incidence of MSSA bacteremia increased from 19.9 to 35.2/100,000 population in Pirkanmaa in parallel to other parts of Finland. The incidence of MRSA bacteremia was 10-fold (4.5/100,000 population) higher in 2011 than in other parts of the country, but sank to the national level (0.59/100,000 population) in 2015. The fatality rate decreased from 22% to 17%. The proportion of penicillin-susceptible Staphylococcus aureus (PSSA) increased from 23.9% in 2008 to 43.1% in 2015. The incidence of both HA and CA SAB has increased since 2005. Conversely, the proportion of MRSA and PRSA bacteremia has decreased. Promotion of infection control measures may have reduced the incidence of MRSA bacteremia but not the overall incidence of SAB. The rising proportion of PSSA enables the use of targeted, narrow spectrum antimicrobials.

[Molecular characterization of resistance mechanisms: methicillin resistance Staphylococcus aureus, extended spectrum β-lactamases and carbapenemases].

PubMed

Oteo, Jesús; Belén Aracil, María

2015-07-01

Multi-drug resistance in bacterial pathogens increases morbidity and mortality in infected patients and it is a threat to public health concern by their high capacity to spread. For both reasons, the rapid detection of multi-drug resistant bacteria is critical. Standard microbiological procedures require 48-72 h to provide the antimicrobial susceptibility results, thus there is emerging interest in the development of rapid detection techniques. In recent years, the use of selective and differential culture-based methods has widely spread. However, the capacity for detecting antibiotic resistance genes and their low turnaround times has made molecular methods a reference for diagnosis of multidrug resistance. This review focusses on the molecular methods for detecting some mechanisms of antibiotic resistance with a high clinical and epidemiological impact: a) Enzymatic resistance to broad spectrum β-lactam antibiotics in Enterobacteriaceae, mainly extended spectrum β-lactamases (ESBL) and carbapenemases; and b) methicillin resistance in Staphylococcus aureus. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Predictive value and cost-effectiveness analysis of a rapid polymerase chain reaction for preoperative detection of nasal carriage of Staphylococcus aureus.

PubMed

Shrestha, Nabin K; Shermock, Kenneth M; Gordon, Steven M; Tuohy, Marion J; Wilson, Deborah A; Cwynar, Roberta E; Banbury, Michael K; Longworth, David L; Isada, Carlos M; Mawhorter, Steven D; Procop, Gary W

2003-05-01

To determine the accuracy and cost-effectiveness of a polymerase chain reaction (PCR) for detecting nasal carriage of Staphylococcus aureus directly from clinical specimens. CROSS-SECTIONAL STUDY: This occurred in a tertiary-care hospital in Cleveland, Ohio, and included 239 consecutive patients who were scheduled for a cardiothoracic surgical procedure. Conventional cultures and a PCR for S. aureus from nasal swabs were used as measurements. COST-EFFECTIVENESS ANALYSIS: Data sources were market prices and Bureau of Labor Statistics. The time horizon was the maximum period for availability of culture results (3 days). Interventions included universal mupirocin therapy without testing; initial therapy, with termination if PCR negative (treat-PCR); initial therapy, with termination if culture negative (treat-culture); treat PCR-positive carriers (PCR-guided treatment); and treat culture-positive carriers (culture-guided treatment). The perspective was institutional and costs and the length of time to treatment were outcome measures. Sixty-seven (28%) of the 239 swabs grew S. aureus. Rapid PCR was 97.0% sensitive and 97.1% specific for the detection of S. aureus. For populations with prevalences of nasal S. aureus carriage of up to 50%, the PCR assay had negative predictive values of greater than 97%. PCR-guided treatment had the lowest incremental cost-effectiveness ratio (1.93 dollars per additional day compared with the culture strategy). Among immediate treatment strategies, treat-PCR was most cost-effective. The universal therapy strategy cost 38.19 dollars more per additional day gained with carrier identification compared with the PCR strategy. Rapid real-time PCR is an accurate, rapid, and cost-effective method for identifying S. aureus carriers for preoperative intervention.

Outbreak of linezolid-resistant Staphylococcus haemolyticus in an Italian intensive care unit.

PubMed

Mazzariol, A; Lo Cascio, G; Kocsis, E; Maccacaro, L; Fontana, R; Cornaglia, G

2012-04-01

We report an outbreak of linezolid-resistant Staphylococcus haemolyticus strains (MIC 32 mg/L) in patients admitted to the Verona University Hospital Intensive Care Unit. The strains proved to be clonally related at pulsed field gel electrophoresis. All the strains showed the G2576T mutation responsible for linezolid-resistance and retained their resistance even after several passages on antibiotic-free medium. After a decade of linezolid use, multifocal emergence of linezolid resistance in coagulase-negative staphylococci has become an important matter of concern and mandates stricter control over the use of this antibiotic in order to preserve its clinical utility.

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

PubMed

Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Changing Pattern of Population Structure of Staphylococcus aureus from Bacteremia in China from 2013 to 2016: ST239-030-MRSA Replaced by ST59-t437.

PubMed

Li, Shuguang; Sun, Shijun; Yang, Chentao; Chen, Hongbin; Yin, Yuyao; Li, Henan; Zhao, Chunjiang; Wang, Hui

2018-01-01

To investigate the epidemiology and genetic structure of Staphylococcus aureus bacteremia in China, a total of 416 isolates from 22 teaching hospitals in 12 cities from 2013 and 2016 were characterized by antibiogram analysis, multilocus sequence typing (MLST), spa typing and staphylococcal cassette chromosome mec (SCC mec ) typing. The predominant meticillin-susceptible (MSSA) genotypes in 2013 were ST188 (19.1%), ST7 (8.7%), and ST398 (7.8%), respectively, and they continued to be the main genotypes in 2016. The prevalence of meticillin-resistant S. aureus (MRSA) were 36.5% (66/181) and 36.6% (86/235) in 2013 and 2016, respectively. Interestingly, the susceptibility rates of MRSA to rifampicin and fluoroquinolones increased significantly from 2013 to 2016 ( P < 0.01), and this was associated with changes in genetic structure. ST239-t030-MRSA, the predominant genotype among all MRSAs in 2013 (34.8%), was replaced by ST59-t437-MRSA (15.1%) in 2016. Further analysis revealed that the ST239-t030-MRSA were more resistant to rifampicin, tetracycline and fluoroquinolones than ST59-t437-MRSA ( P < 0.01). To further gain insight into the mechanisms underlying the changes of genetic structure, in vitro competition and fitness measurements were performed. Importantly, ST239-t030-MRSA displayed lower growth rate and lower competitive advantage compared to ST59-t437-MRSA. Together, our findings reveal that fitness advantage of ST59-t437-MRSA over ST239-t030-MRSA may lead to changes in genetic structure and increased susceptibility of MRSA to rifampicin and fluoroquinolones in Chinese patients with S. aureus bacteremia. Our study supports temporal dynamics in MRSA clone diversities, further providing critical insights into the importance of continued monitoring of MRSA.

Staphylococcus haemolyticus as an Important Hospital Pathogen and Carrier of Methicillin Resistance Genes

PubMed Central

Barros, E. M.; Ceotto, H.; Bastos, M. C. F.; dos Santos, K. R. N.

2012-01-01

Phenotypic and molecular methods were used to characterize the antibiotic resistance of 64 clinical isolates of Staphylococcus haemolyticus. By PCR of the mecA gene, 87% were found to be methicillin resistant. Approximately 55% harbored staphylococcal cassette chromosome mec element (SCCmec) type V, and only one SCCmec type IV. Many isolates (75%) displayed multiresistance, and pulsotype analysis showed a high diversity. PMID:21976766

Staphylococcus haemolyticus as an important hospital pathogen and carrier of methicillin resistance genes.

PubMed

Barros, E M; Ceotto, H; Bastos, M C F; Dos Santos, K R N; Giambiagi-Demarval, M

2012-01-01

Phenotypic and molecular methods were used to characterize the antibiotic resistance of 64 clinical isolates of Staphylococcus haemolyticus. By PCR of the mecA gene, 87% were found to be methicillin resistant. Approximately 55% harbored staphylococcal cassette chromosome mec element (SCCmec) type V, and only one SCCmec type IV. Many isolates (75%) displayed multiresistance, and pulsotype analysis showed a high diversity.

Inhalation of diethylamine--acute nasal effects and subjective response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lundqvist, G.R.; Yamagiwa, M.; Pedersen, O.F.

1992-03-01

Adult volunteers were exposed to 25 ppm (75 mg/m3) diethylamine in a climate chamber for 15 min in order to study the acute nasal reactions to an exposure equivalent to the present threshold limit value-short-term exposure limit. Changes in nasal volume and nasal resistance were measured by acoustic rhinometry and by rhinomanometry. Acute change in nasal volume, usually seen as acute nasal mucosa response to thermal stimuli, was not observed, nor was an acute change in nasal airway resistance. In a subsequent experiment, the aim was to measure acute sensory effects. Exposure to a concentration increasing from 0 to 12more » ppm took place for 60 min, equal to an average concentration of 10 ppm (30 mg/m3). A moderate to strong olfactory response and distinct nasal and eye irritation were observed. In spite of considerable individual variation, the results were in agreement with sensory effect estimates obtained from animal studies.« less

Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

PubMed

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

2015-04-01

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

Heterogeneous resistance to vancomycin in Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains: characterisation of glycopeptide susceptibility profiles and cell wall thickening.

PubMed

Nunes, Ana Paula Ferreira; Teixeira, Lúcia Martins; Iorio, Natália Lopes Pontes; Bastos, Carla Callegário Reis; de Sousa Fonseca, Leila; Souto-Padrón, Thaís; dos Santos, Kátia Regina Netto

2006-04-01

The population analysis profile (PAP) method as well as analysis of autolytic activity and cellular ultrastructure by transmission electron microscopy (TEM) were used to characterise Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains with reduced susceptibility to glycopeptides. All strains showed heterogeneous profiles to vancomycin and teicoplanin by the PAP method. Subpopulations that grew in the presence of high concentrations of each drug were selected from the PAP as derivative strains. Their glycopeptide minimal inhibitory concentrations (MICs) were determined and subsequently all parental and derivative strains were grown in one-half of the MIC of vancomycin or teicoplanin. An increase in cell wall thickness of all derivative strains was seen by TEM, with statistically significant values (P<0.01) compared with their respective parental strains. In general, variable rates of autolysis among the strains were observed. Cell wall thickness is an important factor involved in glycopeptide resistance and, in association with PAP results, confirmed the Brazilian coagulase-negative staphylococci clinical isolates as being heteroresistant to glycopeptides. Detection of these heteroresistant organisms is important in order to achieve more judicious use of vancomycin and teicoplanin in hospitals.

Genetic characterization of Staphylococcus aureus isolated from nasal samples of healthy ewes in Tunisia. High prevalence of CC130 and CC522 lineages.

PubMed

Ben Said, Meriam; Abbassi, Mohamed Salah; Gómez, Paula; Ruiz-Ripa, Laura; Sghaier, Senda; El Fekih, Oussama; Hassen, Abdennaceur; Torres, Carmen

2017-04-01

Staphylococcus aureus is a versatile bacterium, which can infect or colonize a variety of host species. The objective of this study was to characterize S. aureus isolates recovered from nasal swabs of 167 healthy ewes sampled from 12 farms in different areas of Tunisia during the period of 2014-2015. Genetic lineages, virulence factors and antibiotic resistance mechanisms were determined for recovered isolates. S. aureus was detected in 45 out of 167 tested samples (26.9%). All isolates were methicillin-susceptible (MSSA) and the majority of them were susceptible to tested antibiotics with few exceptions (% of resistance): penicillin (8.8), ciprofloxacin (4.4), and tobramycin or tetracycline (2.2, each). Twelve different spa types were detected (t15098, t15099, t1773, t3576, t1534, t5428, t3750, t5970 t254, t2883, t127 and t933), two of them were new (t15098 and t15099). S. aureus isolates were ascribed to agrI (n=23), agrII (n=1) and agrIII (n=20), and one was non-typeable. According to the sequence-type (ST) determined and/or the spa-type detected, the 45S. aureus isolates were assigned to six clonal complexes, with CC522 (44.4%) and CC130 (37.7%) being the most common lineages. Twenty-one (46.6%) and two (4.2%) isolates harbored the tst and eta genes encoding TSST-1 and ETA, respectively. In conclusion, nares of healthy ewes could be a reservoir of MSSA CC522 and CC130, lineages associated with TSST-1 and ETA that might represent a risk to human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transfer of mupirocin resistance from Staphylococcus haemolyticus clinical strains to Staphylococcus aureus through conjugative and mobilizable plasmids.

PubMed

Rossi, Ciro C; Ferreira, Natália C; Coelho, Marcus L V; Schuenck, Ricardo P; Bastos, Maria do Carmo de F; Giambiagi-deMarval, Marcia

2016-07-01

Coagulase-negative staphylococci are thought to act as reservoirs of antibiotic resistance genes that can be transferred to Staphylococcus aureus, thus hindering the combat of this bacterium. In this work, we analyzed the presence of plasmids conferring resistance to the antibiotic mupirocin-widely used to treat and prevent S. aureus infections in hospital environments-in nosocomial S. haemolyticus strains. About 12% of the 75 strains tested were resistant to mupirocin, and this phenotype was correlated with the presence of plasmids. These plasmids were shown to be diverse, being either conjugative or mobilizable, and capable of transferring mupirocin resistance to S. aureus Our findings reinforce that S. haemolyticus, historically and mistakenly considered as a less important pathogen, is a reservoir of resistance genes which can be transferred to other bacteria, such as S. aureus, emphasizing the necessity of more effective strategies to detect and combat this emergent opportunistic pathogen. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Triple-acting Peptidoglycan hydrolase treatment for drug-resistant and intracellular Staphylococcus aureus

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

An Exploratory Descriptive Study of Antimicrobial Resistance Patterns of Staphylococcus Spp. Isolated from Horses Presented at a Veterinary Teaching Hospital.

PubMed

Oguttu, James Wabwire; Qekwana, Daniel Nenene; Odoi, Agricola

2017-08-22

Antimicrobial resistant Staphylococcus are becoming increasingly important in horses because of the zoonotic nature of the pathogens and the associated risks to caregivers and owners. Knowledge of the burden and their antimicrobial resistance patterns are important to inform control strategies. This study is an exploratory descriptive investigation of the burden and antimicrobial drug resistance patterns of Staphylococcus isolates from horses presented at a veterinary teaching hospital in South Africa. Retrospective laboratory clinical records of 1027 horses presented at the University of Pretoria veterinary teaching hospital between 2007 and 2012 were included in the study. Crude and factor-specific percentages of Staphylococcus positive samples, antimicrobial resistant (AMR) and multidrug resistant (MDR) isolates were computed and compared across Staphylococcus spp., geographic locations, seasons, years, breed and sex using Chi-square and Fisher's exact tests. Of the 1027 processed clinical samples, 12.0% were Staphylococcus positive. The majority of the isolates were S. aureus (41.5%) followed by S. pseudintermedius (14.6%). Fifty-two percent of the Staphylococcus positive isolates were AMR while 28.5% were MDR. Significant (p < 0.05) differences in the percentage of samples with isolates that were AMR or MDR was observed across seasons, horse breeds and Staphylococcus spp. Summer season had the highest (64.3%) and autumn the lowest (29.6%) percentages of AMR isolates. Highest percentage of AMR samples were observed among the Boerperds (85.7%) followed by the American saddler (75%) and the European warm blood (73.9%). Significantly (p < 0.001) more S. aureus isolates (72.5%) were AMR than S. pseudintermedius isolates (38.9%). Similarly, significantly (p < 0.001) more S. aureus (52.9%) exhibited MDR than S. pseudintermedius (16.7%). The highest levels of AMR were towards β-lactams (84.5%) followed by trimethoprim/sulfamethoxazole (folate pathway inhibitors

Methicillin-Susceptible Teicoplanin-Resistant Staphylococcus haemolyticus Isolate from a Bloodstream Infection with Novel Mutations in the tcaRAB Teicoplanin Resistance Operon.

PubMed

Bakthavatchalam, Yamuna Devi; Sudarsanam, Thambu David; Babu, Priyanka; Munuswamy, Elakkiya; Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Veeraraghavan, Balaji

2017-07-24

Staphylococcus haemolyticus is a coagulase-negative staphylococcus that is frequently isolated from blood cultures. Here, we report a case of methicillin-susceptible S. haemolyticus that is resistant to teicoplanin (TEC) and heteroresistant to vancomycin (VAN). The isolate was susceptible to cefoxitin and resistant to TEC by Etest. Population analysis profile-area under the curve analysis confirmed the presence of a VAN heteroresistant subpopulation. Next-generation sequencing analysis of the genome revealed the presence of blaZ and msr(A), which encode cross-resistance to macrolide, lincosamide, and streptogramin B, and the quinolone resistance-conferring gene norA. In addition, several amino acid substitutions were observed in the TEC resistance operon tcaRAB, including I3N, I390N, and L450I in tcaA and L44V, G52V, and S87P in tcaR, as well as in the transpeptidase encoding gene walK (D336Y, R375L, and V404A) and L315 and P316 in graS. We hypothesized that this combination of mutations could confer TEC resistance and reduced VAN susceptibility.

Antibiotic resistant airborne bacteria and their multidrug resistance pattern at University teaching referral Hospital in South Ethiopia.

PubMed

Solomon, Fithamlak Bisetegen; Wadilo, Fiseha Wada; Arota, Amsalu Amache; Abraham, Yishak Leka

2017-04-12

Hospitals provide a reservoir of microorganisms, many of which are multi-resistant to antibiotics. Emergence of multi-drug resistant strains in a hospital environment, particularly in developing countries is an increasing problem to infection treatment. This study aims at assessing antibiotic resistant airborne bacterial isolates. A cross-sectional study was conducted at Wolaita Sodo university teaching and referral Hospital. Indoor air samples were collected by using passive air sampling method. Sample processing and antimicrobial susceptibility testing were done following standard bacteriological techniques. The data was analyzed using SPSS version 20. Medically important bacterial pathogens, Coagulase negative staphylococci (29.6%), Staphylococcus aureus (26.3%), Enterococci species, Enterococcus faecalis and Enterococcus faecium (16.5%), Acinetobacter species (9.5%), Escherichia coli (5.8%) and Pseudomonas aeruginosa (5.3%) were isolated. Antibiotic resistance rate ranging from 7.5 to 87.5% was detected for all isolates. Acinetobacter species showed a high rate of resistance for trimethoprim-sulfamethoxazole, gentamicin (78.2%) and ciprofloxacin (82.6%), 28 (38.9%) of S. aureus isolates were meticillin resistant, and 7.5% Enterococci isolates of were vancomycin resistant. 75.3% of all bacterial pathogen were multi-drug resistant. Among them, 74.6% were gram positive and 84% were gram negative. Multi-drug resistance were observed among 84.6% of P. aeruginosa, of 82.5% Enterococcii, E. coli 78.6%, S. aureus 76.6%, and Coagulase negative staphylococci of 73.6%. Indoor environment of the hospital was contaminated with airborne microbiotas, which are common cause of post-surgical site infection in the study area. Bacterial isolates were highly resistant to commonly used antibiotics with high multi-drug resistance percentage. So air quality of hospital environment, in restricted settings deserves attention, and requires long-term surveillance to protect both

Methicillin-Resistant Staphylococcus aureus ST398 from Human Patients, Upper Austria

PubMed Central

Metz-Gercek, Sigrid; Mittermayer, Helmut

2009-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) clonal type ST398 is usually associated with animals. We examined 1,098 confirmed MRSA samples from human patients and found that 21 were MRSA ST398. Most (16) patients were farmers. Increasing prevalence from 1.3% (2006) to 2.5% (2008) shows emergence of MRSA ST398 in humans in Austria. PMID:19402964

New therapeutic choices for infections caused by methicillin-resistant Staphylococcus aureus.

PubMed

Bouza, E

2009-12-01

In recent years, a marked increase in the incidence of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has occurred in many countries. This review addresses the effectiveness and limitations of drugs classically used for the treatment of MRSA, e.g. vancomycin, and also newer anti-MRSA antimicrobials, e.g. second-generation glycolipopeptides, tigecycline, and beta-lactams.

Pharmacokinetic-Pharmacodynamic Modeling of the In Vitro Activities of Oxazolidinone Antimicrobial Agents against Methicillin-Resistant Staphylococcus aureus▿

PubMed Central

Schmidt, Stephan; Sabarinath, Sreedharan Nair; Barbour, April; Abbanat, Darren; Manitpisitkul, Prasarn; Sha, Sue; Derendorf, Hartmut

2009-01-01

Linezolid is the first FDA-approved oxazolidinone with activity against clinically important gram-positive pathogens, including methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). RWJ-416457 is a new oxazolidinone with an antimicrobial spectrum similar to that of linezolid. The goal of the present study was to develop a general pharmacokinetic (PK)-pharmacodynamic (PD) model that allows the characterization and comparison of the in vitro activities of oxazolidinones, determined in time-kill curve experiments, against MRSA. The in vitro activities of RWJ-416457 and the first-in-class representative, linezolid, against MRSA OC2878 were determined in static and dynamic time-kill curve experiments over a wide range of concentrations: 0.125 to 8 μg/ml (MIC, 0.5 μg/ml) and 0.25 to 16 μg/ml (MIC, 1 μg/ml), respectively. After correction for drug degradation during the time-kill curve experiments, a two-subpopulation model was simultaneously fitted to all data in the NONMEM VI program. The robustness of the model and the precision of the parameter estimates were evaluated by internal model validation by nonparametric bootstrap analysis. A two-subpopulation model, consisting of a self-replicating, oxazolidinone-susceptible and a persistent, oxazolidinone-insusceptible pool of bacteria was appropriate for the characterization of the time-kill curve data. The PK-PD model identified was capable of accounting for saturation in growth, delays in the onsets of growth and drug-induced killing, as well as naturally occurring bacterial death. The simultaneous fit of the proposed indirect-response, maximum-effect model to the data resulted in concentrations that produced a half-maximum killing effect that were significantly (P < 0.05) lower for RWJ-416457 (0.41 μg/ml) than for linezolid (1.39 μg/ml). In combination with the appropriate PK data, the susceptibility-based two-subpopulation model identified may provide valuable guidance for the selection of

Lack of Doxycycline Antimalarial Prophylaxis Impact on Staphylococcus aureus Tetracycline Resistance

PubMed Central

Mende, Katrin; Beckius, Miriam L.; Zera, Wendy C.; Yu, Xin; Li, Ping; Tribble, David R.; Murray, Clinton K.

2016-01-01

There is concern that susceptibility of Staphylococcus aureus to tetracyclines may decrease due to use of antimalarial prophylaxis (doxycycline). We examined characteristics related to tetracycline resistance, including doxycycline exposure, in S. aureus isolates collected via admission surveillance swabs and inpatient clinical cultures from United States military personnel injured during deployment (June 2009-January 2012). Tetracycline class resistance was determined using antimicrobial susceptibility testing. The first S. aureus isolate from 168 patients were analyzed, of which 38 (23%) isolates were resistant to tetracyclines (class). Tetracycline-resistant isolates had a higher proportion of resistance to clindamycin (p=0.019) compared to susceptible isolates. There was no significant difference in tetracycline resistance between isolates collected from patients with and without antimalarial prophylaxis; however, significantly more isolates had tet(M) resistance genes in the doxycycline exposure group (p=0.031). Despite 55% of the patients receiving doxycycline as antimalarial prophylaxis, there was no association with resistance to tetracyclines. PMID:27460426

EVALUATION OF THE CHANGES IN THE NASAL CAVITY DURING THE MIGRAINE ATTACK

PubMed Central

Arslan, H. Hüseyin; Tokgöz, Erkan; Yıldızoğlu, Üzeyir; Durmaz, Abdullah; Bek, Semai; Gerek, Mustafa

2012-01-01

Objectives There are some subjective symptoms involving the nasal cavity such as nasal congestion during a migraine attack. In this study, we aimed to evaluate the possible changes occuring in the nasal cavity, during headache in migraine patients. Material and Methods Subjects with migraine were studied. The control group was consisted with tension-type headache patients. The severity of the headache and accompanying complaints were assessed by visual analog scale, and nasal mucosa was assessed by anterior rhinoscopy and endoscopy. Resistance of the nasal cavity was evaluated with anterior rhinomanometry. The data obtained during the attack periods and attack free periods were compared. Results 25 migraine patients and 15 tension-type headache patients were enrolled. It was found that 19 subjects (%76) of migraine group and 5 of tension-type headache group were suffering from nasal congestion during the attack, and that the differences between the groups were statistically significant (p<0.05). The average of total nasal resistance in migraine patients was 0,57±0,60 kPa/L/sn during migraine attacks and 0,28±0,14 kPa/L/sn during attack free periods. The average of total nasal resistance in tension-type headache patients was 0,32±0,14 kPa/L/sn during attack periods and 0,31±0,20 kPa/L/sn during attack free periods. In the migraine group, the change of nasal resistance between during the attack and attack free periods was found statistically significant, while there was no statistically significant difference in the tension-type headache group. Conclusion According to the results of this study, complaining of nasal obstruction and nasal airway resistance increases during migraine attacks. Cause and effect relationship between nasal obstruction and pain is not clear and clinical trials are needed to determine the effect of nasal obstruction treatment (mucosal decongestion etc.) on the complaint of pain. PMID:25072974

In vitro transfer of methicillin resistance determinants mecA from methicillin resistant Staphylococcus aureus (MRSA) to methicillin susceptible Staphylococcus aureus (MSSA).

PubMed

Bitrus, Asinamai Athliamai; Zunita, Zakaria; Bejo, Siti Khairani; Othman, Sarah; Nadzir, Nur Adilah Ahmad

2017-04-04

Staphylococcus aureus more than any other human pathogen is a better model for the study of the adaptive evolution of bacterial resistance to antibiotics, as it has demonstrated a remarkable ability in its response to new antibiotics. This study was designed to investigate the in vitro transfer of mecA gene from methicillin resistant S. aureus to methicillin susceptible S. aureus. The recipient transconjugants were resistant to erythromycin, cefpodoxime and were mecA positive. PCR amplification of mecA after mix culture plating on Luria Bertani agar containing 100 μg/mL showed that 75% of the donor and 58.3% of the recipient transconjugants were mecA positive. Additionally, 61.5% of both the donor cells and recipient transconjugants were mecA positive, while 46.2% and 41.75% of both donor and recipient transconjugants were mecA positive on LB agar containing 50 μg/mL and 30 μg/mL respectively. In this study, the direction of transfer of phenotypic resistance as well as mecA was observed to have occurred from the donor to the recipient strains. This study affirmed the importance of horizontal transfer events in the dissemination of antibiotics resistance among different strains of MRSA.

Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

PubMed Central

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

2015-01-01

Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

Staphylococcus aureus toxin gene hitchhikes on a transferable antibiotic resistance element.

PubMed

Otto, Michael

2010-01-01

Virulence and antibiotic resistance of the dangerous human pathogen Staphylococcus aureus are to large extent determined by the acquisition of mobile genetic elements (MGEs). Up to now, these elements were known to comprise either resistance or virulence determinants, but not a mixture of the two. Queck et al. now found a cytolysin gene of the phenol-soluble modulin (PSM) family within SCCmec elements, which contain methicillin resistance genes and are largely responsible for the spread of methicillin-resistant S. aureus (MRSA). The novel gene, called psm-mec, had a significant impact on virulence in MRSA strains that do not produce high levels of genome-encoded PSMs. This first example of a combination of toxin and resistance genes on one staphylococcal MGE shows that such bundling is possible and may lead to an even faster acquisition of toxin and resistance genes by S. aureus and other staphylococcal pathogens.

Handling a community-acquired methicillin-resistant Staphylococcus aureus outbreak: emerging data.

PubMed

Elston, Dirk M

2008-08-01

Community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA) strains continue to emerge as important causes of sepsis, folliculitis, skin abscesses, necrotizing pneumonitis, empyema, and bone and joint infections. Community-acquired methicillin-resistant S aureus often affects young, previously healthy individuals, including athletes and children in day care. Drainage remains the most important intervention for an abscess. The most common CAMRSA strains in the United States, Canada, and Europe remain sensitive to sulfonamides and tetracycline. Rates of clindamycin resistance vary widely geographically, and physicians should be familiar with their local antibiogram data. Multidrug-resistant strains of CAMRSA are emerging, and the routine addition of antibiotics such as tetracycline to animal feed is contributing to the emergence of resistance. Recurrence and spread of infection can be reduced by addressing the carrier state. Strategies for treatment and elimination of staphylococcal carriage are discussed.

Correlation of Nasal Mucosal Temperature With Subjective Nasal Patency in Healthy Individuals

PubMed Central

Bailey, Ryan S.; Casey, Kevin P.; Pawar, Sachin S.; Garcia, Guilherme J. M.

2016-01-01

Importance Historically, otolaryngologists have focused on nasal resistance to airflow and minimum airspace cross-sectional area as objective measures of nasal obstruction using methods such as rhinomanometry and acoustic rhinometry. However, subjective sensation of nasal patency may be more associated with activation of cold receptors by inspired air than with respiratory effort. Objective To investigate whether subjective nasal patency correlates with nasal mucosal temperature in healthy subjects. Design, Setting, and Participants Twenty-two healthy adults were recruited for this study. Subjects first completed the Nasal Obstruction Symptom Evaluation (NOSE) and a unilateral visual analog scale (VAS) to quantify subjective nasal patency. A miniaturized thermocouple sensor was then used to record nasal mucosal temperature bilaterally in two locations along the nasal septum: at the vestibule and across from the inferior turbinate head. Results The range of temperature oscillations during the breathing cycle, defined as the difference between end-expiratory and end-inspiratory temperatures, was greater during deep breaths (ΔTexp-insp = 6.2 ± 2.6°C) than during resting breathing (ΔTexp-insp = 4.2 ± 2.3°C) in both locations (p < 10−13). Mucosal temperature measured at the right vestibule had a statistically significant correlation with both right-side VAS score (Pearson r = −0.55, p=0.0076) and NOSE score (Pearson r = −0.47, p=0.028). No other statistically significant correlations were found between mucosal temperature and subjective nasal patency scores. Nasal mucosal temperature was lower in the first cavity to be measured, which was the right cavity in all subjects. Conclusions and Relevance The greater mucosal temperature oscillations during deep breathing is consistent with the common experience that airflow sensation is enhanced during deep breaths, thus supporting the hypothesis that mucosal cooling plays a central role in nasal airflow sensation

Towards the Understanding of Resistance Mechanisms in Clinically Isolated Trimethoprim-resistant, Methicillin-resistant Staphylococcus aureus Dihydrofolate Reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frey, K.; Lombardo, M; Wright, D

2010-01-01

Resistance to therapeutics such as trimethoprim-sulfamethoxazole has become an increasing problem in strains of methicillin-resistant Staphylococcus aureus (MRSA). Clinically isolated trimethoprim-resistant strains reveal a double mutation, H30N/F98Y, in dihydrofolate reductase (DHFR). In order to develop novel and effective therapeutics against these resistant strains, we evaluated a series of propargyl-linked antifolate lead compounds for inhibition of the mutant enzyme. For the propargyl-linked antifolates, the F98Y mutation generates minimal (between 1.2- and 6-fold) losses of affinity and the H30N mutation generates greater losses (between 2.4- and 48-fold). Conversely, trimethoprim affinity is largely diminished by the F98Y mutation (36-fold) and is not affectedmore » by the H30N mutation. In order to elucidate a mechanism of resistance, we determined a crystal structure of a complex of this double mutant with a lead propargyl-linked antifolate. This structure suggests a resistance mechanism consistent both for the propargyl-linked class of antifolates and for trimethoprim that is based on the loss of a conserved water-mediated hydrogen bond.« less

Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil.

PubMed

Pereira, M S; Siqueira-Júnior, J P

1995-06-01

Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.

[The importance of wildlife as reservoir of antibiotic-resistant bacteria in Bavaria--first results].

PubMed

Meyer, Cornelia; Heurich, Marco; Huber, Ingrid; Krause, Gladys; Ullrich, Ulrike; Fetsch, Alexandra

2014-01-01

The use of antimicrobial agents is responsible for the emergence and spread of antibiotic resistant bacteria. Nevertheless, multiresistant bacteria have been found in animals that have never been exposed to antimicrobial agents. Wild animals that are carriers of methicillin-resistant organisms represent a hazard since they can transmit their bacteria to other animals and to humans. In the hunting season 2009/2010 nasal swabs of 98 red deer and 109 wild boars were examined for the presence of methicillin-sensitive and methicillin-resistant staphylococci. From each wild boar methicillin-susceptible staphylococci (Staphylococcus aureus in 28% and Staphylococcus spp. in 72% of the animals) were isolated. In red deer the detection rate of Staphylococcus (S.) aureus and methicillin-susceptible staphylococci was 49% and 17%, respectively. The occurrence of S. aureus was significantly higher (p < 0.05) in red deer than in wild boars. Methicillin-resistant staphylococci were not found. However, in one third of the red deer, methicillin-resistant bacteria of the genus Enterococcus spp. and Bacillus spp. were isolated. The results of the present study indicate that wildlife, especially red deer are an important reservoir for S. aureus and that the upper respiratory tract of red deer is regularly colonised with methicillin-resistant bacteria such as Bacillus spp. and Enterococcus spp. Primarily, commensal bacteria are harmless to human health, however, red deer may be a reservoir for antibiotic-resistant bacteria.

Regional peak mucosal cooling predicts the perception of nasal patency.

PubMed

Zhao, Kai; Jiang, Jianbo; Blacker, Kara; Lyman, Brian; Dalton, Pamela; Cowart, Beverly J; Pribitkin, Edmund A

2014-03-01

Nasal obstruction is the principal symptom that drives patients with rhinosinus disease to seek medical treatment. However, patient perception of obstruction often bears little relationship to actual measured physical obstruction of airflow. This lack of an objective clinical tool hinders effective diagnosis and treatment. Previous work has suggested that the perception of nasal patency may involve nasal trigeminal activation by cool inspiratory airflow; we attempt to derive clinically relevant variables following this phenomenon. Prospective healthy cohort. Twenty-two healthy subjects rated unilateral nasal patency in controlled room air using a visual analog scale, followed by rhinomanometry, acoustic rhinometry, and butanol lateralization thresholds (BLTs). Each subject then immediately underwent a computed tomography scan, enabling the construction of a real-time computational fluid dynamics (CFD) nasal airway model, which was used to simulate nasal mucosa heat loss during steady resting breathing. Among all measured and computed variables, only CFD-simulated peak heat loss posterior to the nasal vestibule significantly correlated with patency ratings (r = -0.46, P < .01). Linear discriminant analysis predicted patency categories with 89% success rate, with BLT and rhinomanometric nasal resistance being two additional significant variables. As validation, CFD simulated nasal resistance significantly correlated with rhinomanometrically measured resistance (r = 0.41, P < .01). These results reveal that our noses are sensing patency via a mechanism involving localized peak nasal mucosal cooling. The analysis provides a strong rationale for combining the individualized CFD with other objective and neurologic measures to create a novel clinical tool to diagnose nasal obstruction and to predict and evaluate treatment outcomes. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Patterns and predictors of antimicrobial resistance among Staphylococcus spp. from canine clinical cases presented at a veterinary academic hospital in South Africa.

PubMed

Qekwana, Daniel N; Oguttu, James W; Sithole, Fortune; Odoi, Agricola

2017-04-28

Antimicrobial resistance in staphylococci, often associated with treatment failure, is increasingly reported in veterinary medicine. The aim of this study was to investigate patterns and predictors of antimicrobial resistance among Staphylococcus spp. isolates from canine samples submitted to the bacteriology laboratory at the University of Pretoria academic veterinary hospital between 2007 and 2012. Retrospective data of 334 Staphylococcus isolates were used to calculate the proportion of samples resistant to 15 antimicrobial agents. The Cochran-Armitage trend test was used to investigate temporal trends and logistic regression models were used to investigate predictors of antimicrobial resistance in Staphylococcus aureus and Staphylococcus pseudintermedius. Results show that 98.2% (55/56) of the S. aureus isolates were resistant to at least one drug while 42.9% were multidrug resistant. Seventy-seven percent (214/278) of the S. pseudintermedius isolates were resistant to at least one drug and 25.9% (72/278) were multidrug resistant. Resistance to lincospectin was more common among S. aureus (64.3%) than S. pseudintermedius (38.9%). Similarly, resistance to clindamycin was higher in S. aureus (51.8%) than S. pseudintermedius (31.7%) isolates. There was a significant (p = 0.005) increase in S. aureus resistance to enrofloxacin over the study period. Similarly, S. pseudintermedius exhibited significant increasing temporal trend in resistance to trimethoprim-sulphamethoxazole (p = 0.004), clindamycin (p = 0.022) and orbifloxacin (p = 0.042). However, there was a significant decreasing temporal trend in the proportion of isolates resistant to doxycycline (p = 0.041), tylosin (p = 0.008), kanamycin (p = 0.017) and amoxicillin/clavulanic acid (p = 0.032). High levels of multidrug resistance and the increasing levels of resistance to sulphonamides, lincosamides and fluoroquinolones among Staphylococcus spp. isolates in this study are concerning. Future

The effect of mouth leak and humidification during nasal non-invasive ventilation.

PubMed

Tuggey, Justin M; Delmastro, Monica; Elliott, Mark W

2007-09-01

Poor mask fit and mouth leak are associated with nasal symptoms and poor sleep quality in patients receiving domiciliary non-invasive ventilation (NIV) through a nasal mask. Normal subjects receiving continuous positive airways pressure demonstrate increased nasal resistance following periods of mouth leak. This study explores the effect of mouth leak during pressure-targeted nasal NIV, and whether this results in increased nasal resistance and consequently a reduction in effective ventilatory support. A randomised crossover study of 16 normal subjects was performed on separate days. Comparison was made of the effect of 5 min of mouth leak during daytime nasal NIV with and without heated humidification. Expired tidal volume (V(T)), nasal resistance (R(N)), and patient comfort were measured. Mean change (Delta) in V(T) and R(N) were significantly less following mouth leak with heated humidification compared to the without (DeltaV(T) -36+/-65 ml vs. -88+/-50 ml, p<0.001; DeltaR(N) +0.9+/-0.4 vs. +2.0+/-0.7 cm H(2)O l s(-1), p<0.001). Baseline comfort was worse without humidification (5.3+/-0.4 vs. 6.2+/-0.4, p<0.01), and only deteriorated following mouth leak without humidification. In normal subjects, heated humidification during nasal NIV attenuates the adverse effects of mouth leak on effective tidal volume, nasal resistance and improves overall comfort. Heated humidification should be considered as part of an approach to patients who are troubled with nasal symptoms, once leak has been minimised.

Increasing rate of daptomycin non-susceptible strains of Staphylococcus aureus in patients with atopic dermatitis.

PubMed

Błażewicz, Izabela; Jaśkiewicz, Maciej; Piechowicz, Lidia; Neubauer, Damian; Nowicki, Roman J; Kamysz, Wojciech; Barańska-Rybak, Wioletta

2017-12-01

Daptomycin is a cyclic lipopeptide that is bactericidal against Staphylococcus aureus , including methicillin-resistant S. aureus (MRSA), vancomycin-intermediate S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA) strains. Daptomycin exerts its antimicrobial effect by a calcium-dependent interaction with the cytoplasmic membrane resulting in depolarization, ion loss and rapid cell death. Unfortunately, loss of daptomycin susceptibility in S. aureus in the clinical setting has been noted. To evaluate the susceptibility profile to daptomycin among S. aureus strains isloted from patients with atopic dermatitis (AD). Another point was to correlate the results obtained by broth microdilution method and Etest, which is commonly applied in clinical setting. One hundred patients with the diagnosis of atopic dermatitis were microbiologically assessed for the carriage of S. aureus . Antimicrobial susceptibility tests were performed using broth-microdilution (BMD) and Etests for daptomycin. Staphylococcus aureus strains were isolated from the majority of our patients, either from the skin (73%) or the anterior nares (75%). Six of the 100 nasal swabs (6%) and 5 of the 100 skin swabs (5%) were positive for methicillin-resistant Staphylococcus aureus (MRSA). A total of 81 of 148 (54.7%) daptomycin non-susceptible isolates of S. aureus were identified by BMD. Only 19 of 81 were also classified as non-susceptible by Etest. Clinicians and microbiologists should be aware of the possibility of the emergence of daptomycin non-susceptibility (or increase in minimal inhibitory concentration) during prolonged therapy and closely monitor the susceptibility of persisting isolates that might be recovered during therapy.

Contamination of public transports by Staphylococcus aureus and its carriage by biomedical students: point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains.

PubMed

Mendes, Â; Martins da Costa, P; Rego, D; Beça, N; Alves, C; Moreira, T; Conceição, T; Aires-de-Sousa, M

2015-08-01

To analyse the contamination of public transports by Staphylococcus aureus and assess its carriage by biomedical students, focussing on the point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains. Cross-sectional survey. Methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolated from handrails of buses (n = 112) and trains (n = 79) circulating in Porto and from nasal swabs of local university students (n = 475) were quantified, characterized by molecular typing methods and related to possible risk factors. The MRSA prevalence in buses (16.1%) was not significantly different from trains (8.9%). There was also no identifiable association between the counts of MSSA and MRSA in buses and trains and the number of travellers in each sampling day, specific routes (including those passing by main hospitals) or other risk factors. Of the students, 37.1% carried S. aureus, and having a part-time job or smoking were found to be risk factors for carriage. EMRSA-15 (ST22-SCCmecIVh) was the prevalent MRSA clonal lineage, found not only in the buses (n = 14) and trains (n = 2) but also in the single MRSA-carrier among the students. The characteristics of the community-associated Southwest Pacific MRSA clone were found in a single ST30-IVa isolate, which may suggest a recent SCCmec acquisition by an MSSA background in the community. The spread of EMRSA-15, a common hospital-associated lineage, among different public transports and as a nasal coloniser is of concern and warrants adequate public health control measures. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Genetic basis for the resistance of Staphylococcus aureus to peptidoglycan hydrolase by comparative transcriptome and whole genome sequence analysis

USDA-ARS?s Scientific Manuscript database

Background: Lysostaphin is a glycyl-glycine bacteriocin peptidoglycan hydrolase secreted by Staphylococcus simulans for degrading the peptidoglycan moieties in Staphylococcus aureus cell walls which result in cell lysis. There are known mechanisms of resistance to lysostaphin, e.g. serine in place...

Activity of delafloxacin against methicillin-resistant Staphylococcus aureus: resistance selection and characterization.

PubMed

Remy, Joan M; Tow-Keogh, Cheryl A; McConnell, Timothy S; Dalton, James M; Devito, Joseph A

2012-12-01

To determine the potential for delafloxacin to select for resistant mutants in methicillin-resistant Staphylococcus aureus (MRSA), including isolates with existing mutations in the quinolone resistance determining region (QRDR). Susceptibility testing by broth microdilution was performed on 30 MRSA clinical isolates. For four of these isolates, the presence or absence of mutations in the QRDR was characterized. Resistance selection was performed on these four isolates by spreading cells on drug-containing agar plates followed by incubation for 48 h. Resistance frequencies and mutant prevention concentrations (MPCs) were calculated for each; PCR amplification and sequencing were performed using standard methods to characterize mutations in the QRDR. Growth rate analysis was performed and relative fitness was determined. Delafloxacin demonstrated potent in vitro activity against this set of MRSA isolates, with MICs of 0.008-1 mg/L and an MIC(50) and MIC(90) of 0.03 and 0.5 mg/L, respectively. Spontaneous delafloxacin resistance frequencies for the MRSA strains were 2 × 10(-9) to <9.5 × 10(-11). Delafloxacin MPCs were one to four times the MIC for any isolate, lower than those of comparator quinolones. Some delafloxacin-selected mutants showed a fitness cost when co-cultured with the parent strain. Delafloxacin demonstrates excellent antibacterial potency and exhibits a low probability for the selection of resistant mutants in MRSA. Although mutants can be selected at low frequencies in vitro from quinolone-resistant isolates, delafloxacin MICs and MPCs remain low and a fitness cost can be observed. Consequently delafloxacin warrants further investigation for the potential treatment of drug-resistant MRSA infections.

mecC-Harboring Methicillin-Resistant Staphylococcus aureus: Hiding in Plain Sight.

PubMed

Ford, Bradley A

2018-01-01

Previously there was scant data on the performance of laboratory testing to detect mecC -mediated beta-lactam resistance in Staphylococcus aureus Kriegeskorte and colleagues (J Clin Microbiol 56:e00826-17, 2018, https://doi.org/10.1128/JCM.00826-17) report the performance of various clinical tests for the detection of mecC -harboring methicillin-resistant S. aureus (MRSA), which failed to identify from 0 to 41% of tested mecC -harboring MRSA isolates. Changes in practice and new test development are necessary to address the challenge of mecC -harboring MRSA. Copyright © 2017 American Society for Microbiology.

Isolation and characterization of methicillin-resistant Staphylococcus aureus from pork farms and visiting veterinary students.

PubMed

Frana, Timothy S; Beahm, Aleigh R; Hanson, Blake M; Kinyon, Joann M; Layman, Lori L; Karriker, Locke A; Ramirez, Alejandro; Smith, Tara C

2013-01-01

In the last decade livestock-associated methicillin-resistant S. aureus (LA-MRSA) has become a public health concern in many parts of the world. Sequence type 398 (ST398) has been the most commonly reported type of LA-MRSA. While many studies have focused on long-term exposure experienced by swine workers, this study focuses on short-term exposures experienced by veterinary students conducting diagnostic investigations. The objectives were to assess the rate of MRSA acquisition and longevity of carriage in students exposed to pork farms and characterize the recovered MRSA isolates. Student nasal swabs were collected immediately before and after farm visits. Pig nasal swabs and environmental sponge samples were also collected. MRSA isolates were identified biochemically and molecularly including spa typing and antimicrobial susceptibility testing. Thirty (30) veterinary students were enrolled and 40 pork farms were visited. MRSA was detected in 30% of the pork farms and in 22% of the students following an exposure to a MRSA-positive pork farm. All students found to be MRSA-positive initially following farm visit were negative for MRSA within 24 hours post visit. Most common spa types recovered were t002 (79%), t034 (16%) and t548 (4%). Spa types found in pork farms closely matched those recovered from students with few exceptions. Resistance levels to antimicrobials varied, but resistance was most commonly seen for spectinomycin, tetracyclines and neomycin. Non-ST398 MRSA isolates were more likely to be resistant to florfenicol and neomycin as well as more likely to be multidrug resistant compared to ST398 MRSA isolates. These findings indicate that MRSA can be recovered from persons visiting contaminated farms. However, the duration of carriage was very brief and most likely represents contamination of nasal passages rather than biological colonization. The most common spa types found in this study were associated with ST5 and expands the range of livestock

Management of methicillin-resistant Staphylococcus aureus bacteremia.

PubMed

Cosgrove, Sara E; Fowler, Vance G

2008-06-01

Staphylococcus aureus bacteremia and endocarditis are serious infections that demand prompt clinical attention to ensure good outcomes. Of foremost importance is identifying and managing the source of infection and any associated complications. Evaluation for the presence of cardiac involvement is essential because inadequately managed S. aureus endocarditis is life threatening. Thus, physicians must aggressively negotiate treatment paths, considering whether the S. aureus bacteremia is complicated, whether foreign sources of infection should be removed or replaced, and whether surgical intervention is necessary. Selection of an antibiotic treatment is also an essential factor for optimal management. The increasing prevalence of methicillin-resistant S. aureus (MRSA) infections has created a tremendous demand for effective and safe antimicrobial agents other than the historic anti-MRSA agent vancomycin.

High prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene in a semi-extensive red deer (Cervus elaphus hispanicus) farm in Southern Spain.

PubMed

Gómez, Paula; Lozano, Carmen; González-Barrio, David; Zarazaga, Myriam; Ruiz-Fons, Francisco; Torres, Carmen

2015-06-12

The objective was to determine the prevalence of Staphylococcus aureus nasal carriage in red deer of a semi-extensive farm and in humans in contact with the estate animals, and to characterize obtained isolates. Nasal swabs of 65 deer and 15 humans were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base. Isolates were identified by microbiological and molecular methods. Antimicrobial susceptibility profile was determined for 16 antibiotics by disk-diffusion and the presence of eight antibiotic resistance genes, seven virulence genes and genes of immune-evasion-cluster (IEC) was analyzed by PCR. S. aureus was typed by PFGE-SmaI, spa, agr, SCCmec and MLST. Isolates were detected in 16 deer (24.6%). Eleven S. aureus isolates were methicillin-resistant (MRSA), and five were methicillin-susceptible (MSSA). All MRSA harbored mecC gene and were agr-III/SCCmecXI/ST1945 (four spa-t843 and seven spa-t1535). All mecC-MRSA carried blaZ-SCCmecXI and etd2, were IEC-type-E, and belonged to the same PFGE pattern. The five MSSA were typed as spa-t2420/agr-I/ST133. Regarding humans, S. aureus was recovered from six samples (40%). The isolates were MSSA and were typed as spa-t002/agr-II, spa-t012/agr-III or spa-t822/agr-III and showed different IEC types (A, B, D and F). blaZ and erm(A) genes were detected, as well as cna and tst genes. As conclusion, red deer analyzed in this study are frequent carriers of mecC-MRSA CC130 (16.9%), they are characterized by few resistance and virulence determinants, and by the presence of IEC type-E. Deer could be a source of mecC-MRSA which could potentially be transmitted to other animals, or even to humans. Copyright © 2015 Elsevier B.V. All rights reserved.

The importance of side difference in nasal obstruction and rhinomanometry: a retrospective correlation of symptoms and rhinomanometry in 1000 patients.

PubMed

Thulesius, H L; Cervin, A; Jessen, M

2012-02-01

The correlation between subjective and objective outcomes of nasal obstruction is still a matter of controversy. The aim of this study was to determine the minimal level of side difference in nasal airway resistance (NAR measured by Broms'v(2)) between the two nasal cavities, which could be discerned subjectively by the patient on a visual analogue scale (VAS). Nasal airway resistance was calculated from rhinomanometric measurements of nasal airflow and transnasal pressure after decongestion of the nasal mucosa. A retrospective study. ENT department, Vaxjo Central Hospital, Sweden. We studied 1000 active anterior rhinomanometries from patients with nasal obstructions. We compared the side difference of nasal airway resistance with the side difference of VAS estimated immediately prior to the rhinomanometry. Each measurement was performed after nasal decongestion. When the difference in nasal airway resistance between the two nasal cavities was larger than 20° (Broms'v(2)) or R(2) > 0.36 Pa/cm(3) /s, we found a significant correlation between side differences of the objective measurement and the subjective assessment (VAS). With a nasal airway resistance side difference over 20°, an additional 20° difference corresponded to a 0.9 centimetre average VAS change. The more obstructed side of the nose could be determined by VAS in 823 (82.3%) of 1000 patients. Yet, 177 (17.7%) patients had a paradoxical sensation of nasal obstruction with the low resistance side of the nose experienced as the most congested side. A significant correlation between the side differences of nasal airway resistance and VAS can serve as a supplement to rhinoscopy in decisions about nasal surgery. This study also showed that in 17.7% of patients, there was a negative correlation between subjective and objective evaluations of nasal airway resistance. But in this group, the nasal airway resistance side difference was mostly under 20°. © 2011 Blackwell Publishing Ltd.

Genotypic diversity of methicillin-resistant Staphylococcus aureus isolates in Korean hospitals.

PubMed

Soo Ko, Kwan; Kim, Yeon-Sook; Song, Jae-Hoon; Yeom, Joon-Sup; Lee, Hyuck; Jung, Sook-In; Jeong, Doo-Ryun; Kim, Shin-Woo; Chang, Hyun-Ha; Ki, Hyun Kyun; Moon, Chisook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2005-08-01

Ninety-six methicillin-resistant Staphylococcus aureus (MRSA) isolates from eight Korean hospitals were analyzed by multilocus sequence typing, SCCmec typing, and spa typing. The predominant genotype was ST5-MRSA-II of clonal complex 5, which was found in 36 isolates from six hospitals, but ST239-MRSA-III was also common. Overall, results showed a notable genotypic diversity of MRSA strains circulating in Korean hospitals.

Resistance to antimicrobials and biofilm formation in Staphylococcus spp. isolated from bovine mastitis in the Northeast of Brazil.

PubMed

da Costa Krewer, Carina; Santos Amanso, Evandro; Veneroni Gouveia, Gisele; de Lima Souza, Renata; da Costa, Mateus Matiuzzi; Aparecido Mota, Rinaldo

2015-03-01

Mastitis is the principal disease affecting dairy herds worldwide. The aim of the present study was to characterize phenotypic and genotypic features associated with resistance to antimicrobials in Staphylococcus spp. isolated from 2064 milk samples of 525 lactating cows in the Northeast of Brazil. Of the 218 isolates analyzed, 57.8% were characterized as Staphylococcus aureus, 28% as coagulase-positive staphylococci other than S. aureus (oCPS), and 14.2% as coagulase-negative staphylococci (CNS). The test for susceptibility to antimicrobials showed amoxicillin (32.6%) to be the less effective drug in vitro, and the multi-drug resistance (MDR) rate for beta-lactams varied from 0 to 0.75. The genotypic characterization showed that 93.1% of the samples were tested positive for the blaZ gene, while none amplified mecA. The antibiotic efflux mechanism was observed in 0.9% of isolates. The biofilm formation was found in 3.7 and 96.3% of samples, respectively, on Congo red agar and on the microplate adhesion test, while the icaD gene was present in 92.2% of Staphylococcus spp. The high frequency of blaZ gene observed in this study was associated with the resistance of most Staphylococcus spp. to one or more of the beta-lactams tested, which are routinely used in Brazilian herds for mastitis treatment. The biofilm formation was also detected in the isolates analyzed being an important characteristic for pathogenicity and antimicrobial resistance of bacteria.

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

PubMed Central

Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

2014-01-01

There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

Bacteriological profiling of diphenylureas as a novel class of antibiotics against methicillin-resistant Staphylococcus aureus

PubMed Central

Younis, Waleed; Ezzat, Hany G.; Peters, Christine E.; AbdelKhalek, Ahmed; Cooper, Bruce; Pogliano, Kit; Pogliano, Joe; Mayhoub, Abdelrahman S.; Seleem, Mohamed N.

2017-01-01

Bacterial resistance to antibiotics remains an imposing global public health challenge. Of the most serious pathogens, methicillin-resistant Staphylococcus aureus (MRSA) is problematic given strains have emerged that exhibit resistance to several antibiotic classes including β-lactams and agents of last resort such as vancomycin. New antibacterial agents composed of unique chemical scaffolds are needed to counter this public health challenge. The present study examines two synthetic diphenylurea compounds 1 and 2 that inhibit growth of clinically-relevant isolates of MRSA at concentrations as low as 4 µg/mL and are non-toxic to human colorectal cells at concentrations up to 128 μg/mL. Both compounds exhibit rapid bactericidal activity, completely eliminating a high inoculum of MRSA within four hours. MRSA mutants exhibiting resistance to 1 and 2 could not be isolated, indicating a low likelihood of rapid resistance emerging to these compounds. Bacterial cytological profiling revealed the diphenylureas exert their antibacterial activity by targeting bacterial cell wall synthesis. Both compounds demonstrate the ability to resensitize vancomycin-resistant Staphylococcus aureus to the effect of vancomycin. The present study lays the foundation for further investigation and development of diphenylurea compounds as a new class of antibacterial agents. PMID:28797064

Phenotypic and Molecular Antibiotic Resistance Determination of Airborne Coagulase Negative Staphylococcus spp. Strains from Healthcare Facilities in Southern Poland.

PubMed

Lenart-Boroń, Anna; Wolny-Koładka, Katarzyna; Stec, Joanna; Kasprowic, Andrzej

2016-10-01

This study assessed the antimicrobial resistance of airborne Staphylococcus spp. strains isolated from healthcare facilities in southern Poland. A total of 55 isolates, belonging to 10 coagulase-negative staphylococci (CoNS) species, isolated from 10 healthcare facilities (including hospitals and outpatient units) were included in the analysis. The most frequently identified species were Staphylococcus saprophyticus and Staphylococcus warneri, which belong to normal human skin flora, but can also be the cause of common and even severe nosocomial infections. Disk diffusion tests showed that the bacterial strains were most frequently resistant to erythromycin and tetracycline and only 18% of strains were susceptible to all tested antimicrobials. Polymerase chain reaction amplification of specific gene regions was used to determine the presence of the Macrolide-Lincosamide-Streptogramin resistance mechanisms in CoNS. The molecular analysis, conducted using specific primer pairs, identified the msrA1 gene, encoding active efflux pumps in bacterial cells, as the most frequent resistance gene. As many as seven antibiotic resistance genes were found in one isolate, whereas the most common number of resistance genes per isolate was five (n = 17). It may be concluded that drug resistance was widely spread among the tested strains, but the resulting antimicrobial resistance profile indicates that in the case of infection, the use of antibiotics from the basic antibiogram group will be effective in therapy. However, before administering treatment, determination of the specific antimicrobial resistance should be conducted, particularly in the case of hospitalized patients.

Community-associated methicillin resistant Staphylococcus aureus in south Florida hospital and recreational environments

USDA-ARS?s Scientific Manuscript database

Strains of methicillin resistant Staphylococcus aureus (MRSA), a frequent human pathogen, may also be found in the flora of healthy persons and in the environments that they frequent. Strains of MRSA circulating in the community classified as USA 300 are now found not only in the community but also...

Linezolid-resistant Staphylococcus haemolyticus and Staphylococcus hominis: single and double mutations at the domain V of 23S rRNA among isolates from a Rio de Janeiro hospital.

PubMed

Chamon, Raiane Cardoso; Iorio, Natalia Lopes Pontes; Cavalcante, Fernanda Sampaio; Teodoro, Cristiane R S; de Oliveira, Ana Paula Chaves; Maia, Fernanda; dos Santos, Kátia Regina Netto

2014-12-01

In this work, the molecular and phenotypic antimicrobial resistance and clonal diversity of 10 linezolid-resistant Staphylococcus spp. isolates were investigated. The 7 Staphylococcus haemolyticus isolates presented Staphylococcal cassete chromosome mec (SCCmec) V and belonged to the same pulsed-field gel electrophoresis pulsotype. Their MICs for oxacillin, vancomycin, and linezolid were ≥ 256 μg/mL, 1-4 μg/mL, and 8-16 μg/mL, respectively. The 3 S. hominis presented MIC values 32 to >256 μg/mL, 2-4 μg/mL, and 12-24 μg/mL, and all carried the nontypeable SCCmec (ccr1 + mecA class) and belonged to 2 different genotypes. The cfr gene was not found, but the mutation G2603T was detected in S. haemolyticus and C2190T and G2603T in Staphylococcus hominis in 23S rRNA. This study demonstrates the spread of a linezolid-resistant S. haemolyticus genotype and, for the first time, describes the mutation C2190T among S. hominis isolates with a double mutation in Brazil. Copyright © 2014 Elsevier Inc. All rights reserved.

Effectiveness of a Glycylcycline Antibiotic for Reducing the Pathogenicity of Superantigen-Producing Methicillin-Resistant Staphylococcus aureus in Burn Wounds

PubMed Central

Nosanov, Lauren B.; Jo, Daniel Y.; Randad, Pranay R.; Moffatt, Lauren T.; Carney, Bonnie C.; Ortiz, Rachel T.

2017-01-01

Objective: Burn-injured patients are highly susceptible to infectious complications, which are often associated with increased morbidity and mortality. Rates of antibiotic resistance have increased, and resistant species such as methicillin-resistant Staphylococcus aureus provide additional challenges in the form of virulence factors. Proteins can disrupt local healing, leading to systemic immune disruption. To optimize outcomes, treatments that reduce pathogenicity must be identified. This study aims to compare a glycylcycline antibiotic—tigecycline—with clindamycin for effectiveness in treating superantigenic methicillin-resistant Staphylococcus aureus in burn wounds. Methods: Sprague-Dawley rats received paired 2 × 2-cm burn wounds, which were subsequently inoculated with known virulence factor–producing methicillin-resistant Staphylococcus aureus or media alone on postinjury day 1. Infected animals received twice-daily tigecycline (high or low dose), twice-daily clindamycin (high or low dose), or saline alone (positive controls). Daily sampling and imaging assessments were performed. Results: Bacterial counts and toxin levels were reduced significantly in antibiotic-treated groups relative to positive controls (P < .001). Results from day 7 showed measurable toxin levels in clindamycin-treated, but not tigecycline-treated, wounds. Imaging analysis revealed a return of wound perfusion in tigecycline-treated animals similar to the sham animals. Transcript analysis using polymerase chain reaction and polymerase chain reaction arrays demonstrated downregulation of gene expression in antibiotic-treated animals as compared with positive controls. Conclusions: Overall, this study supports the use of tigecycline in the treatment of methicillin-resistant Staphylococcus aureus–infected burn wounds. While both protein synthesis inhibitors are effective, tigecycline appears to be superior in controlling toxin levels, enabling better wound healing. PMID:28943993

Effectiveness of a Glycylcycline Antibiotic for Reducing the Pathogenicity of Superantigen-Producing Methicillin-Resistant Staphylococcus aureus in Burn Wounds.

PubMed

Nosanov, Lauren B; Jo, Daniel Y; Randad, Pranay R; Moffatt, Lauren T; Carney, Bonnie C; Ortiz, Rachel T; Shupp, Jeffrey W

2017-01-01

Objective : Burn-injured patients are highly susceptible to infectious complications, which are often associated with increased morbidity and mortality. Rates of antibiotic resistance have increased, and resistant species such as methicillin-resistant Staphylococcus aureus provide additional challenges in the form of virulence factors. Proteins can disrupt local healing, leading to systemic immune disruption. To optimize outcomes, treatments that reduce pathogenicity must be identified. This study aims to compare a glycylcycline antibiotic-tigecycline-with clindamycin for effectiveness in treating superantigenic methicillin-resistant Staphylococcus aureus in burn wounds. Methods : Sprague-Dawley rats received paired 2 × 2-cm burn wounds, which were subsequently inoculated with known virulence factor-producing methicillin-resistant Staphylococcus aureus or media alone on postinjury day 1. Infected animals received twice-daily tigecycline (high or low dose), twice-daily clindamycin (high or low dose), or saline alone (positive controls). Daily sampling and imaging assessments were performed. Results : Bacterial counts and toxin levels were reduced significantly in antibiotic-treated groups relative to positive controls ( P < .001). Results from day 7 showed measurable toxin levels in clindamycin-treated, but not tigecycline-treated, wounds. Imaging analysis revealed a return of wound perfusion in tigecycline-treated animals similar to the sham animals. Transcript analysis using polymerase chain reaction and polymerase chain reaction arrays demonstrated downregulation of gene expression in antibiotic-treated animals as compared with positive controls. Conclusions : Overall, this study supports the use of tigecycline in the treatment of methicillin-resistant Staphylococcus aureus -infected burn wounds. While both protein synthesis inhibitors are effective, tigecycline appears to be superior in controlling toxin levels, enabling better wound healing.

Genotypic Diversity of Methicillin-Resistant Staphylococcus aureus Isolates in Korean Hospitals

PubMed Central

Soo Ko, Kwan; Kim, Yeon-Sook; Song, Jae-Hoon; Yeom, Joon-Sup; Lee, Hyuck; Jung, Sook-In; Jeong, Doo-Ryun; Kim, Shin-Woo; Chang, Hyun-Ha; Ki, Hyun Kyun; Moon, Chisook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2005-01-01

Ninety-six methicillin-resistant Staphylococcus aureus (MRSA) isolates from eight Korean hospitals were analyzed by multilocus sequence typing, SCCmec typing, and spa typing. The predominant genotype was ST5-MRSA-II of clonal complex 5, which was found in 36 isolates from six hospitals, but ST239-MRSA-III was also common. Overall, results showed a notable genotypic diversity of MRSA strains circulating in Korean hospitals. PMID:16048991

Correlation of Nasal Mucosal Temperature With Subjective Nasal Patency in Healthy Individuals.

PubMed

Bailey, Ryan S; Casey, Kevin P; Pawar, Sachin S; Garcia, Guilherme J M

2017-01-01

Historically, otolaryngologists have focused on nasal resistance to airflow and minimum airspace cross-sectional area as objective measures of nasal obstruction using methods such as rhinomanometry and acoustic rhinometry. However, subjective sensation of nasal patency may be more associated with activation of cold receptors by inspired air than with respiratory effort. To investigate whether subjective nasal patency correlates with nasal mucosal temperature in healthy individuals. Healthy adult volunteers first completed the Nasal Obstruction Symptom Evaluation (NOSE) and a unilateral visual analog scale to quantify subjective nasal patency. A miniaturized thermocouple sensor was then used to record nasal mucosal temperature bilaterally in 2 locations along the nasal septum: at the vestibule and across from the inferior turbinate head. Nasal mucosal temperature and subjective patency scores in healthy individuals. The 22 healthy adult volunteers (12 [55%] male; mean [SD] age, 28.3 [7.0] years) had a mean (SD) NOSE score of 5.9 (8.4) (range, 0-30) and unilateral VAS score of 1.2 (1.4) (range, 0-5). The range of temperature oscillations during the breathing cycle, defined as the difference between end-expiratory and end-inspiratory temperatures, was greater during deep breaths (mean [SD] change in temperature, 6.2°C [2.6°C]) than during resting breathing (mean [SD] change in temperature, 4.2°C [2.3°C]) in both locations (P < .001). Mucosal temperature measured at the right vestibule had a statistically significant correlation with both right-side visual analog scale score (Pearson r = -0.55; 95% CI, -0.79 to -0.17; P = .008) and NOSE score (Pearson r = -0.47; 95% CI, -0.74 to -0.06; P = .03). No other statistically significant correlations were found between mucosal temperature and subjective nasal patency scores. Nasal mucosal temperature was lower (mean of 1.5°C lower) in the first cavity to be measured, which was the right cavity in all

Disinfection of rigid nasal endoscopes following in vitro contamination with Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae.

PubMed

Bradford, Benjamin D; Seiberling, Kristin A; Park, Francine E; Hiebert, Jared C; Chang, Dennis F

2013-06-01

If not adequately cleaned, rigid nasal endoscopes (RNEs) have the potential to cause iatrogenic cross-contamination. To test the efficacy of various disinfection methods in reducing bacterial load on RNEs in vitro. In vitro model. Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae contamination was separately induced on RNEs in vitro. Two experimental sets were completed. The RNEs were disinfected using the following protocols: 30-second scrub with antimicrobial soap (ABS) and water, 30-second scrub with 70% isopropyl alcohol (IA), 30-second scrub with ABS followed by 30-second scrub with IA, 30-second scrub with germicidal cloth, isolated 5-minute soak in an enzymatic soap solution, 5- and 10-minute soaks in ortho-phthalaldehyde, 0.55%, solution (Cidex OPA), and isolated 30-second rinse with tap water, all with 30-second precleaning and postcleaning rinses with tap water. Two sets of experiments (experiment sets A and B) were carried out with a 30-second tap water rinse after inoculation of each RNE. This was followed by immediate cleaning in set A and a 1-hour air-dry delay in set B. Otherwise there were no differences in the disinfection protocols between sets for each method noted. Effectiveness of various disinfection protocols in cleaning rigid nasal endoscopes experimentally inoculated with bacteria commonly found in the upper aerodigestive tract. Positive cultures following disinfection indicated ineffective or incomplete disinfection. Most cleaning methods were effective in eliminating S aureus, S pneumoniae, and H influenzae from the scopes following experimental contamination. Continued growth of P aeruginosa was found after all of the disinfection trials in experiment set A with the exception of a 10-minute immersion in Cidex OPA, and in set B except for the 10-minute Cidex OPA immersion and ABS plus IA trials. Most cleaning methods used in our trials appear to properly disinfect RNEs after in vitro

Frequency of efflux pump genes mediating ciprofloxacin and antiseptic resistance in methicillin-resistant Staphylococcus aureus isolates.

PubMed

Hassanzadeh, Sepideh; Mashhadi, Rahil; Yousefi, Masoud; Askari, Emran; Saniei, Maryam; Pourmand, Mohammad Reza

2017-10-01

Efflux pumps are well known as a key role to fluoroquinolone resistance in methicillin-resistant Staphylococcus aureus (MRSA). In this study, among 60 clinical MRSA isolates, 42 isolates (70%) were resistant to ciprofloxacin. MRSA were isolated to detect efflux genes including norA, norB, norC, mepA, sepA, mdeA, qacA/B and smr. Isolates subjected to PCR detection and DNA sequence analysis for these genes. PCR detection showed that 42 isolates (70%) contained at least one efflux pump gene. Among ciprofloxacin-resistant isolates, mdeA and qacA/B genes were found with the highest (61.7%) and lowest (3.3%) frequency, respectively. We also observed that the highest minimum inhibitory concentrations of ciprofloxacin in the presence of mdeA+mepA+norA-C+sepA+smr combination. This type of combination may have the greatest impact on resistance to ciprofloxacin. Finally, compared to previous studies, our study demonstrates that prevalence of ciprofloxacin resistance has been increasing among MRSA clinical isolates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effectiveness of simple control measures on methicillin-resistant Staphylococcus aureus infection status and characteristics with susceptibility patterns in a teaching hospital in Peshawar.

PubMed

Rafiq, Muhammad Salman; Rafiq, Muhammad Imran; Khan, Taimur; Rafiq, Maria; Khan, Mah Muneer

2015-09-01

To determine the effectiveness of simple control measures on the infection status and characteristics of methicillin-resistant Staphylococcus aureus including susceptibility patterns among health professionals and patients in a teaching hospital. The cross-sectional study was conducted from September 2013 to January 2014, and comprised samples collected from healthcare personnel and patients in the various units of Khyber Teaching Hospital, Peshawar. The specimens were collected before and one month after the implementation of simple control measures for outbreak prevention of methicillin-resistant Staphylococcus aureus. These were tested for culture and antimicrobial susceptibility. Data about methicillin-sensitive and methicillin-resistant Staphylococcus aureus infection, wound characteristics and susceptibility patterns was collected and effectiveness of simple control measures was determined. SPSS 20 was used for statistical analysis. Of the total 390 isolates, 180(46.2%) were Staphylococcus aureus; 77(19.7%) from healthcare personnel and 103(26.4%) from patients. Of these, 164(42.1%) were methicillin-sensitive and 16(4.1%) were methicillin-resistant. Among the patients, 38(15.1%) methicillin-sensitive and 8(3.2%) methicillin-resistant isolates were recovered from wounds or skin and soft tissues. Pus with 33(13.1%) and 4(1.6%) cases respectively was the second most common source. Among methicillin-resistant isolates, resistance to Linezolid was 0%, all were resistant to Oxacillin, Cefoxitin, Amoxicillin, Cefotaxime and Cephradine, and resistance to both Co-Amoxiclav and Ciprofloxacin was 87.5%. After one month of implementation of simple control measures, the number of methicillin-resistant cases among healthcare professionals and patients dropped from 4(2.9%) and 7(10.8%) to 1(0.7%) and 5(2.7%), respectively. Methicillin-resistant and methicillin-sensitive Staphylococcus aureus differed in their anti-microbial susceptibility profiles. Selection of antibiotics

Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis

PubMed Central

Ciftci, Alper; Findik, Arzu; Onuk, Ertan Emek; Savasan, Serap

2009-01-01

This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7%) were positive for mecA gene. Although 22 of 59 (37.2%) S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains. PMID:24031354

PBP-2 Negative Methicillin Resistant Staphylococcus schleiferi Bacteremia from a Prostate Abscess: An Unusual Occurrence

PubMed Central

Merchant, Chandni; Villanueva, Daphne-Dominique; Lalani, Ishan; Eng, Margaret; Kang, Yong

2016-01-01

Staphylococcus schleiferi subsp. schleiferi is a coagulase-negative Staphylococcus which has been described as a pathogen responsible for various nosocomial infections including bacteremia, brain abscess, and infection of intravenous pacemakers. Recently, such bacteria have been described to be found typically on skin and mucosal surfaces. It is also believed to be a part of the preaxillary human flora and more frequently found in men. It is very similar in its pathogenicity with Staphylococcus aureus group and expresses a fibronectin binding protein. Literature on this pathogen reveals that it commonly causes otitis among dogs because of its location in the auditory meatus of canines. Also, it has strong association with pyoderma in dogs. The prime concern with this organism is the antibiotic resistance and relapse even after appropriate treatment. Very rarely, if any, cases have been reported about prostatic abscess (PA) with this microbe. Our patient had a history of recurrent UTIs and subsequent PA resulting in S. schleiferi bacteremia in contrast to gram negative bacteremia commonly associated with UTI. This organism was found to be resistant to methicillin, in spite of being negative for PBP2, which is a rare phenomenon and needs further studies. PMID:27092283

Bactericidal Effects of Charged Silver Nanoparticles in Methicillin-resistant Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Romero-Urbina, Dulce; Velazquez-Salazar, J. Jesus; Lara, Humberto H.; Arellano-Jimenez, Josefina; Larios, Eduardo; Yuan, Tony T.; Hwang, Yoon; Desilva, Mauris N.; Jose-Yacaman, Miguel

2015-03-01

The increased number of infections due to antibiotic-resistant bacteria is a major concern to society. The objective of this work is to determine the effect of positively charged AgNPs on methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus(MRSA) cell wall using advanced electron microscopy techniques. Positively charged AgNPs suspensions were synthesized via a microwave heating technique. The suspensions were then characterized by Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) showing AgNPs size range from 5 to 30 nm. MSSA and MRSA were treated with positively charged AgNPs concentrations ranging from 0.06 mM to 31 mM. The MIC50 studies showed that viability of MSSA and MRSA could be reduced by 50% at a positively charged AgNPs concentration of 0.12 mM supported by Scanning-TEM (STEM) images demonstrating bacteria cell wall disruption leading to lysis after treatment with AgNPs. The results provide insights into one mechanism in which positively charged AgNPs are able to reduce the viability of MSSA and MRSA. This research is supported by National Institute on Minority Health and Health Disparities (G12MD007591) from NIH, NSF-PREM Grant No. DMR-0934218, The Welch Foundation and NAMRU-SA work number G1009.

Correlation between nasal obstruction symptoms and objective parameters of acoustic rhinometry and rhinomanometry.

PubMed

Kim, C S; Moon, B K; Jung, D H; Min, Y G

1998-01-01

Acoustic rhinometry and rhinomanometry have been used to assess nasal airway patency objectively. We compared nasal obstruction symptoms before and after decongestion with several parameters of these objective tests. The patients assessed their nasal obstruction using a visual analogue scale (VAS). Cross-sectional areas and nasal resistance were measured by acoustic rhinometry and rhinomanometry before and after topical application of 1% phenylephrine solution in 32 patients with nasal obstruction symptoms. There was no significant correlation between the difference in the VAS and the difference in nasal resistance. There was also no significant correlation between the difference in the VAS and minimal cross-sectional area and cross-sectional areas at 3.3 cm (CA3.3), CA4.0 and CA6.4 from the nosepiece both in the wide and narrow sides and in both nasal cavities before and after nasal decongestion. It is concluded that rhinomanometry and acoustic rhinometry may have no diagnostic value in estimating the severity of nasal obstruction symptoms.

Feeding of waste milk to Holstein calves affects antimicrobial resistance of Escherichia coli and Pasteurella multocida isolated from fecal and nasal swabs.

PubMed

Maynou, G; Bach, A; Terré, M

2017-04-01

The use of milk containing antimicrobial residues in calf feeding programs has been shown to select for resistant fecal Escherichia coli in dairy calves. However, information is scarce about the effects of feeding calves waste milk (WM) on the prevalence of multidrug-resistant bacteria. The objective of this study was to determine the antimicrobial resistance patterns of fecal E. coli and nasal Pasteurella multocida isolates from calves fed either milk replacer (MR) or WM in 8 commercial dairy farms (4 farms per feeding program). Fecal and nasal swabs were collected from 20 ± 5 dairy calves at 42 ± 3.2 d of age, and from 10 of these at approximately 1 yr of age in each study farm to isolate the targeted bacteria. Furthermore, resistance of E. coli isolates from calf-environment and from 5 calves at birth and their dams was also evaluated in each study farm. Resistances were tested against the following antimicrobial agents: amoxicillin-clavulanic acid, ceftiofur, colistin, doxycycline (DO), enrofloxacin (ENR), erythromycin, florfenicol, imipenem, and streptomycin. A greater number of fecal E. coli resistant to ENR, florfenicol, and streptomycin and more multidrug-resistant E. coli phenotypes were isolated in feces of calves fed WM than in those fed MR. However, the prevalence of fecal-resistant E. coli was also influenced by calf age, as it increased from birth to 6 wk of age for ENR and DO and decreased from 6 wk to 1 yr of age for DO regardless of the feeding program. From nasal samples, an increase in the prevalence of colistin-resistant P. multocida was observed in calves fed WM compared with those fed MR. The resistance patterns of E. coli isolates from calves and their dams tended to differ, whereas similar resistance profiles among E. coli isolates from farm environment and calves were observed. The findings of this study suggest that feeding calves WM fosters the presence of resistant bacteria in the lower gut and respiratory tracts of dairy calves

Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

PubMed Central

Sowash, Madeleine G.; Uhlemann, Anne-Catrin

2014-01-01

Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

Bacterial microbiome of the nose of healthy dogs and dogs with nasal disease

PubMed Central

Dorn, Elisabeth S.; Suchodolski, Jan S.; Nisar, Tariq; Ravindran, Prajesh; Weber, Karin; Hartmann, Katrin; Schulz, Bianka S.

2017-01-01

The role of bacterial communities in canine nasal disease has not been studied so far using next generation sequencing methods. Sequencing of bacterial 16S rRNA genes has revealed that the canine upper respiratory tract harbors a diverse microbial community; however, changes in the composition of nasal bacterial communities in dogs with nasal disease have not been described so far. Aim of the study was to characterize the nasal microbiome of healthy dogs and compare it to that of dogs with histologically confirmed nasal neoplasia and chronic rhinitis. Nasal swabs were collected from healthy dogs (n = 23), dogs with malignant nasal neoplasia (n = 16), and dogs with chronic rhinitis (n = 8). Bacterial DNA was extracted and sequencing of the bacterial 16S rRNA gene was performed. Data were analyzed using Quantitative Insights Into Microbial Ecology (QIIME). A total of 376 Operational Taxonomic Units out of 26 bacterial phyla were detected. In healthy dogs, Moraxella spp. was the most common species, followed by Phyllobacterium spp., Cardiobacteriaceae, and Staphylococcus spp. While Moraxella spp. were significantly decreased in diseased compared to healthy dogs (p = 0.005), Pasteurellaceae were significantly increased (p = 0.001). Analysis of similarities used on the unweighted UniFrac distance metric (p = 0.027) was significantly different when nasal microbial communities of healthy dogs were compared to those of dogs with nasal disease. The study showed that the canine nasal cavity is inhabited by a highly species-rich bacterial community, and suggests significant differences between the nasal microbiome of healthy dogs and dogs with nasal disease. PMID:28459886

Bacterial microbiome of the nose of healthy dogs and dogs with nasal disease.

PubMed

Tress, Barbara; Dorn, Elisabeth S; Suchodolski, Jan S; Nisar, Tariq; Ravindran, Prajesh; Weber, Karin; Hartmann, Katrin; Schulz, Bianka S

2017-01-01

The role of bacterial communities in canine nasal disease has not been studied so far using next generation sequencing methods. Sequencing of bacterial 16S rRNA genes has revealed that the canine upper respiratory tract harbors a diverse microbial community; however, changes in the composition of nasal bacterial communities in dogs with nasal disease have not been described so far. Aim of the study was to characterize the nasal microbiome of healthy dogs and compare it to that of dogs with histologically confirmed nasal neoplasia and chronic rhinitis. Nasal swabs were collected from healthy dogs (n = 23), dogs with malignant nasal neoplasia (n = 16), and dogs with chronic rhinitis (n = 8). Bacterial DNA was extracted and sequencing of the bacterial 16S rRNA gene was performed. Data were analyzed using Quantitative Insights Into Microbial Ecology (QIIME). A total of 376 Operational Taxonomic Units out of 26 bacterial phyla were detected. In healthy dogs, Moraxella spp. was the most common species, followed by Phyllobacterium spp., Cardiobacteriaceae, and Staphylococcus spp. While Moraxella spp. were significantly decreased in diseased compared to healthy dogs (p = 0.005), Pasteurellaceae were significantly increased (p = 0.001). Analysis of similarities used on the unweighted UniFrac distance metric (p = 0.027) was significantly different when nasal microbial communities of healthy dogs were compared to those of dogs with nasal disease. The study showed that the canine nasal cavity is inhabited by a highly species-rich bacterial community, and suggests significant differences between the nasal microbiome of healthy dogs and dogs with nasal disease.

[Spread of genetically related methicillin-susceptible Staphylococcus aureus belonging to CC45, in healthy nasal carriers in Child Day Care Centers of Medellin, Colombia].

PubMed

Rodríguez-Tamayo, Erika Andrea; Ruiz-Cadavid, Alejandra; Sánchez-González, Leidy Maritza; García-Valencia, Natalia; Jiménez-Quiceno, Judy Natalia

2016-03-01